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THE    PRINCIPLES 

OF 

HYGIENE 

A  Practical   Manual  for   Students, 

Physicians,  and  Health-Officers 

BY 

D,  H^BERGEY,  A.  M.,  M,  D.,  Dr»  R  H. 

Assistant  Professor  of  Hygiene  and  Bacteriology,  University  of 
Pennsylvania 

SIXTH  EDITION,  THOROUGHLY  REVISED 

PHILADELPHIA    AND    LONDON 

W,    B.    SAUNDERS     COMPANY 

J9I8 

Copyright,  1901,  by  W.  B.  Saunders  and  Company.     Revised,  reprinted,  and 
rei:opyrighted  June,  1904.     Reprinted  INIay,  1906.     Revised,  reprinted, 
and    recopyrighted    January,    1909.      Reprinted    May,    1910. 
Revised,  reprinted,  and  recopyrighted  January,  1912. 
Revised,  reprinted,  and  recopyrighted  Sep- 
tember, 1914.     Revised,  reprinted, 
and  recopyrighted  January, 
IQ18 


Copyright,  1918,  by  W.  B.  Saunders  Company 


154^5 


PRINTED    IN    AMERICA 


PRESS    OF 
SAUNDERS    COMPANY 
PHILADELPHIA 


PREFACE  TO  THE  SIXTH    EDITION. 


Since  the  previous  edition  has  been  issued  the 
advancement  of  our  knowledge  of  hygiene  has  con- 
tinued, and  it  has  been  necessary  to  ampHfy  the  text 
in  many  particulars.  This  has  been  a  period  of  general 
advancement,  so  that  no  particular  phase  of  the  subject 
has  progressed  to  a  greater  extent  than  any  other. 

In  order  to  maintain  the  relative  size  of  the  volume 
an  effort  has  been  made  to  eliminate  any  part  of  the 
text  that  appeared  least  essential  to  the  uniform  treat- 
ment of  the  entire  subject. 

As  in  the  past,  it  has  been  a  pleasure  to  accept  the 
helpful  suggestions  of  the  reviewers. 

It  is  hoped  that  this  edition  of  the  book  may  receive 
the  same  cordial  approval  that  has  been  accorded  to 
the  other  editions. 

D.  H.  B. 

January,  191S. 


PREFACE. 


This  book  has  been  prepared  to  meet  the  needs  of 
students  of  medicine  in  the  acquirement  of  a  knowledge 
of  those  principles  on  which  modern  hygienic  practices 
are  based ;  to  aid  students  in  architecture  in  comprehend- 
ing the  sanitary  requirements  in  ventilation,  heating, 
water-supply,  and  sewage-disposal;  and  to  aid  physicians 
and  health  ofl&cers  in  familiarizing  themselves  with  the 
advances  made  in  hygienic  practices  in  recent  years. 

The  rapid  strides  made  in  our  knowledge  of  the  entire 
subject  of  hygiene  has  rendered  such  a  book,  based  upon 
the  more  recent  discoveries,  almost  a  necessity  to  students 
of  medicine. 

No  attempt  has  been  made  to  treat  the  subject  in  an 
exhaustive  manner,  the  object  being  merely  to  give  the 
general  principles  upon  which  the  health  officer  and  the 
physician  work  in  their  respective  capacities  in  dealing 
with  conditions  which  are  detrimental  to  health  or  which 
tend  to  improve  health. 

The  entire  range  of  subjects  comprising  the  compre- 
hensive field  of  hygiene  has  not  been  discussed,  but  all 
those  subjects  which  appeared  to  the  author  to  be  most 
important  for  those  for  whom  the  book  has  been  pre- 
pared have  received  the  consideration  which  their  relative 
importance  demanded. 

The  metric  system  of  weights  and  measures  has  been 
employed  throughout  the  work    except    in    quotations, 

9 


lO  PREFACE. 

because  this  system  is  now  in  general  use  in  all  scientific 
laboratories  in  the  United  States,  and  because  it  is  in 
every  way  preferable  to  the  cumbersome  and  complicated 
system,  with  its  various  units,  which  is  still  in  common 
use.  The  metric  system  was  employed  also  because  it  is 
in  common  use  on  the  Continent  of  Europe,  and  is  also  a 
legal  system  in  the  United  States  since  1866,  when  Con- 
gress passed  an  act  making  its  use  lawful  in  the  construc- 
tion of  contracts  and  in  all  legal  proceedings.  It  is 
rapidly  coming  into  general  use  in  medicine  and  phar- 
macy, and  its  general  adoption  has  the  hearty  endorse- 
ment of  numerous  scientific  societies.  At  the  present 
time  a  bill  is  passing  through  Congress  which,  when 
enacted,  will  make  its  employment  compulsory  in  all 
departments  of  the  Government  after  January  i,  1903. 
In  the  Appendix  the  relative  values  of  the  units  of 
weights  and  measures  of  the  metric  system  have  been 
given  in  terms  of  the  English  system,  and  vice  versa. 

D.  H.  B. 


-  CONTENTS 


PAGE 

Introduction 17 

Causes  of  Disease,  17. — Sanitary  Science,  28. — Hygiene,  28. 

CHAPTER  I. 

Air 32 

Nature  and  Composition  of  the  Atmosphere,  32. — Temperature  of 
the  Air,  34. — Pressure  of  the  Atmosphere,  35. — Distribution  of  At- 
mospheric Pressure,  37. — Humidity  of  the  Atmosphere,  38. — 
Hygrometry,  39. — Elastic  Force  of  Vapor,  41. — Absolute  Humidity, 
.  41. — Relative  Humidity,  41. — The  Influence  of  Humidity  on  Health, 
42. — Movements  of  the  Atmosphere,  42. — Clouds,  43. — Precipitation 
of  Moisture,  43. — Climate,  44. — Ground-air,  52. — Sewer-air,  52. — 
The  Impurities  in  the  Air,  53 . — Examination  of  the  Air  by  the  Senses, 
58. — Chemical  Analysis  of  the  Air,  59. — Diseases  Produced  by 
Impure  Air,  62. — Effects  of  Vitiated  Air  Generally,  63. 

CHAPTER  II. 

Ventilation 67 

Amount  of  Fresh  Air  Required,  67. — Cubic  Space,  69. — General 
Rules  for  Ventilation,  71. — Natural  Ventilation,  71. — Arrangements 
in  Natural  Ventilation,  73. — Artificial  Ventilation,  81. — Removal  of 
Dust,  86  — Humidifying  the  Air,  88. 

CHAPTER  III. 

Heating go 

Loss  of  Heat  from  Buildings,  90. — Degree  of  Warmth,  90. — Heat 
Supplied  by  Radiating  Surfaces,  91. — Systems  of  Heating,  93. — 
Direct  Heating,  94. — Indirect  Heating,  97. 

CHAPTER  IV. 

Water  and  Water-supply 100 

Physical  Properties  of  Water,  100. — Chemical  Composition,  100. — 
Rain-water,  loi. — Spring-water,  loi. — Well-water,  102. — River- 
water,  102. — Lake- water,  103. — Sea-water,  103. — Impurities  in 
Water,  103. — Odors  in  Drinking-water,  107. — Effects  of  Impurities  in 
Water,  108. — Dissolved  Impurities,  109. — Approximate  Composition 


12  CONTENTS. 

PAGE 

of  Drinking-water,  114. — ^Amount  of  Drinking-water  Required  Daily, 
115. — Source  of  Water-supplies,  116. — Storage  of  Water,  121. — 
Purification  of  Water,  121. — Methods  of  Purification,  122. — Steriliza- 
tion of  Water  by  Means  of  Chemicals,  141. — Suitability  of  Water  for 
Boiler  Purposes,  143. — Standard  Method  of  Water  and  Sewage 
Analysis,  145. 

CHAPTER  V. 

The  Remov.^  axd  Disposal  of  Sewage 151 

The  Removal  of  Sewage,  151. — Water-closets,  151. — ^Traps,  154. 
—Disposal  of  Sewage,  158. — Chemical  Treatment  of  Sewage,  160. 
— ^Modern  Methods  of  Sewage  Purification,  162. — Sprinkling  Filters, 
168. — The  Removal  of  Sewage  by  Liernur  System,  170.— Commer- 
cial Value  of  Sewage,  171. 

CHAPTER  VI. 

Garbage  Disposal 173 

Collection  and  Removal  of  Garbage,  174. — Disposal  of  Garbage, 
ITS- 
CHAPTER  VII. 

Food  and  Dieting 178 

Chemical  Composition  of  the  Body,  178. — Potential  Energy  in 
Food,  180. — ^Energy  Derivable  from  Food,  182. — Nutritive  Value 
and  Cost  of  Food,  189. — Digestibility  of  Foods,  191. — Composition 
of  Foods,  193. — Functions  of  the  Alimentary  Principles  of  Food, 
194. — ^Water  as  Food,  195. — Different  Varieties  of  Food,  196. — 
Animal  Foods:  Meat,  196. — Food-poisoning,  200. — Composition  of 
Meat,  206. — Fish,  208. — Milk  and  ]\Iilk-products,  208. — Vegetable 
Foods,  221. — Bread,  222. — Preserved  Meats,  224. — Preserved  Vege- 
table Foods,  224. — Food-preservatives,  225. — Nuts  and  Their  Uses 
as  Food,  226. — Mineral  Food,  226. — Beverages  and  Condiments, 
227. — ^Adulterations  of  Food,  228. — Dietaries,  232. — Nutritional 
Diseases,  236. 

CHAPTER  VIII. 

Exercise 239 

Effect  on  the  Lungs,  239. — Effect  on  the  Circulation,  241. — Effect 
on  the  Muscles,  242. — Fatigue,  242. — Effect  on  the  Nervous  Sys- 
tem, 243. — Effect  on  the  Elimination  of  Nitrogen,  243. — Amount  of 
Exercise  that  Should  Be  Taken,  244. 

CHAPTER  rX. 

Clothing 247 

Protection  against  Cold,  247. — Protection  against  Heat,  248. — 
Protection  against  Dampness,  248. — Protection  against  Injury,  249. 
— Injurious  Effects  of  Clothing,  251. — Cleanliness  in  Relation  to 
Clothing,  252. — Infected  Clothes  and  Bedding,  253. 


CONTENTS.      .  13 

CHAPTER  X.  PAGE 

Personal  Hygiene 254 

Cleanliness,  255. — The  Bowels,  255. — The  Passions,  255. — The 
Mouth  and  Teeth,  255. — Habitation,  256. — Occupation,  256. — 
Mental  Attitude,  257. 

CHAPTER  XI. 

Industrial  Hygiene 258 

The  Effect  of  Anilin  Dyes  and  Nitrobenzine  and  Its  Compounds, 
272. — Special  Industrial  Diseases,  274. — Influence  of  the  Length  of 
the  Working-day  on  the  Health  of  the  Laborers,  276. — Lighting  of 
Industrial  Establishments,  278. 

CHAPTER  XII. 

School  Hygiene 281 

Site,  or  Location,  with  Reference  to  Drainage  Capacity  of  the 
Soil,  281. — Structure  of  the  Walls,  282. — Cubic  Space  and  Floor 
Space,  282. — Relation  of  Window  Space  to  Cubic  Space,  284. — 
Lighting,  285.— The  Position  of  Blackboards,  286.— Corridors, 
Cloak-rooms,  and  Wardrobes,  286.— Ventilation,  287.— Heating, 
288. — Water-supply  and  Sewage  Disposal,  289. — Water-closets  and 
Latrines,  290. — Desks  and  Seats,  290. — Defects  in  School-buildings, 
292. — Medical  Inspection  of  Schools,  295. 

CHAPTER  XIII. 

Military  Hygiene 302 

The  Recruit,  302. — Training  of  the  Recruit,  305. — Food  of  the 
Soldier,  306. — Clothing  of  the  Soldier,  308. — Camps,  31 2. — Barracks, 
315. — Marches,  317. — Camp  Diseases,  318. — Antityphoid  Vaccina- 
tion, 320. — Foot  Inspection,  322. — Body  Inspection,  323. 

CHAPTER  XIV. 

Naval  Hygiene 324 

Ventilation,  325. — Heating  of  the  Vessel,  3 2 7. ^Lighting,  327. — 
Cleansing  the  Vessel,  327. — Water-supply,  327. — Food-supply,  328. 
— Clothing,  329. — Selection  of  Marines,  329. — Principal  Diseases 
Among  Mariners,  333. 

CHAPTER  XV. 

Soil 335 

Ground-air,  335. — Ground-water,  336.— Pathogenic  Bacteria  in 
Soil,  338. — Improvement  of  a  Damp  Soil,  338. — Configuration  of  the 
Surface  and  Soil-covering,  338. 

CHAPTER  XVI. 

Habitations 34° 

Position  of  the  House,  340. — The  Foundation  and  Walls,  341. — 
The  Roof,  341. — The  Interior  Arrangement,  342. — The  Size  of  the 
Rooms,  342. — The  Sleeping-rooms,  343. — The  Floors  and   Floor- 


14  CONTENTS. 

PAGE 

coverings,  344. — The  Wall-coverings,  344. — Ventilation  and  Heating, 
345. — Cooling  Devices,  346. — Plumbing  and  Drainage,  348. — Houses 
for  the  Poor,  348. — House-cleaning,  350. — Protection  from  Flies  and 
Mosquitoes,  351. 

CHAPTER  XVII. 

Vital  Causes  of  Disease 352 

Modes  of  Dissemination,  354.— Nature  of  Epidemics,  355.— Im- 
munity and  Susceptibility,  356. — Prevention  of  Infection  by  Induc- 
ing Active  Immunity,  373. — The  Haffkine  Method  of  Protection, 
374. — Value  of  Vaccination  as  a  Protective  against  Small-pox,  379. — 
Precautions  in  Vaccination,  383.— Biologic  Aids  to  Diagnosis,  384.— 
Personal  Prophylaxis,  386. — Persistence  of  Pathogenic  Bacteria 
in  Dead  Bodies,  390. — Transmission  of  Relapsing  Fever,  391. — 
Prevention  of  MalaVia,  392. — Prevention  of  Yellow  Fever,  395.^ 
Destruction  of  Vermin,  400. — Relation  of  Insects  to  the  Spread  of 
Disease,  402. — Remedies  for  Fleas,  408. — Animal  Parasites,  411. — 
Prevention  of  Infection  with  Animal  Parasites,  423. — Vegetable 
Parasites,  425. 

CHAPTER  XVIII. 

Disinfection 428 

Disinfectants  in  Common  Use,  430. — The  Action  of  Sunlight  on 
Bacteria,  with  Special  Reference  to  Bacillus  Tuberculosis,  430. — 
Disinfection  on  Large  Scale,  431. — Formaldehyd,  432. — Generation 
of  Formaldehyd  Gas,  433. — Liquid  Formaldehyd-spraying,  436. — 
Sulphur  Dioxid,  436. — Hydrocyanic  Acid,  437. — Corrosive  Subli- 
mate, 437. — Carbolic  Acid,  438. — Trikresol,  438. — Creolin,  439. — 
Nitrate  of  Silver,  439. — Preparations  of  Lime,  439. — Washing  Soda, 
439. — Sulphate  of  Iron,  439. — Physical  Agents,  440. — Disinfection  of 
Infective  Materials,  441. — Disinfection  of  Excreta,  441. — Disin- 
fection of  Sick-room,  442. — Disinfection  of  Habitations,  444. — Dis- 
infection of  Patient,  445. — Disinfection  of  Public  Conveyances,  446. 
— Disinfection  of  Libraries,  448. — Barber-shops,  448. 

CHAPTER  XIX. 

Quarantine 450 

Maritime  Quarantine,  450. — Inland  Quarantine,  451. — Isolation 
or  House  Quarantine,  452. — Value  of  Disinfection  and  Isolation,  452. 
— Period  of  Isolation,  456. — Period  of  Detention  of  Those  Exposed 
to  the  Infectious  Diseases,  456. — Maritime  Quarantine,  457. — Quar- 
antine Laws  of  the  United  States,  458. — Quarantine  Regulations,  473. 
— Foreign  and  Insular  Regulations,  477. — Interstate  Quarantine, 
507.— State  Quarantine  Regulations,  511. — House  Quarantine,  513. 

CHAPTER  XX. 

Vital  Statistics 517 

The  Census  as  a  Basis  for  Calculation,  519. — Standards  of  Age- 
distribution,  519. — Calculation  of  the  Birth-rate  and  the  Death-rate, 


CONTENTS.  15 

PAGE 

521. — Rate  of  Infant  Mortality,  522. — Death-rate  of  Persons  En- 
gaged in  Various  Occupations,  522. — Mortality  in  Relation  to  Sea- 
sons, 523. — Mean  Age  at  Death,  523. — Mean  Duration  of  Life,  523. 
— ^Probable  Duration  of  Life,  524. — Expectation  of  Life,  524. — Rela- 
tion of  Density  of  Population  to  the  Death-rate,  525. — Necessity  of 
System  of  Notification,  526. — Hospital  for  Infectious  Diseases,  527. 


Appendix 528 

Rules  for  Interchange  of  Different  Expressions  of  Results  of  Anal- 
ysis, 528. — Rules  for  Conversion  of  Degrees  of  One  Thermometer 
Scale  into  those  of  Another,  528. — Rules  for  Conversion  of  Kilo- 
gram-meters into  Foot-pounds  and  Foot- tons,  and  vice  versa,  529. — 
Values  of  Terms  Employed  in  Connection  with  Fuel-value  of  Food, 
529. — Comparison  of  Metric  and  English  Weights  and  Measures,  529. 

Index 531 


THE 

PRINCIPLES  OF  HYGIENE 


INTRODUCTION. 


The  comprehensive  nature  of  the  subject  precludes 
the  possibility  of  giving  a  short  and  precise  definition. 
A  late  writer  on  hygiene  has  given  the  following  defini- 
tion :  "  Hygiene  aims  to  make  growth  more  perfect,  life 
more  vigorous,  decay  less  rapid,  death  more  remote," 
Hence  hygiene  treats  of  the  laws  of  health  ;  of  all  those 
measures  which  tend  to  preserve  the  body  in  a  healthy 
condition,  as  well  as  those  which  tend  to  improve  the 
general  health.  It  embraces  a  knowledge  of  the  factors 
and  conditions  which  bring  about  ill  health  and  disease, 
as  well  as  a  knowledge  of  the  methods  of  preventing 
disease,  and  of  the  measures  which  tend  to  fortify  and 
improve  the  organism. 

Health  is  that  condition  of  the  body  in  which  all  the 
various  functions  are  performed  normally,  and  without 
the  manifestation  of  discomfort  in  any  of  its  operations. 
Disease,  on  the  other  hand,  implies  the  imperfect  per- 
formance of  one  or  more  of  the  bodily  functions  because 
of  the  impaired  structure  of  the  corresponding  organ  or 
organs,  and  the  consequent  manifestation  of  discomfort, 
either  in  the  part  directly  affected  or  in  the  body  generally. 

There  are  many  factors  which  may  operate  in  such  a 
manner  as  to  bring  about  disease.  These  factors  are 
usually  divided  into  the  immediate  and  remote  causes  of 
disease. 

The  immediate  causes  of  disease  may  be  again  divided 
into  three  classes,   physical,  chemical,   and  vital.     The 

2  17 


l8  INTRODUCTION. 

physical  causes  of  disease  are  such  as  are  brought  about 
by  physical  agencies.  The  diseases  which  are  due  to 
physical  agencies  are  burns,  cuts,  bruises,  fractures,  and 
the  like,  and  those  diseases  of  the  respiratory  organs  due 
to  the  inhalation  of  various  forms  of  dust.  The  chemical 
causes  of  disease  are  corrosive  and  irritating  drugs  and 
chemicals  which  act  directly  through  their  corrosive  action 
upon  the  part  with  which  they  are  brought  in  contact, 
or  indirectly  through  action  upon  the  system  after  having 
been  absorbed  into  the  circulation.  The  vital  causes  of 
disease  are  the  most  important,  because  they  are  the  most 
numerous  and  are  frequently  communicated  from  the 
sick  to  the  well.  They  are  also  of  great  hygienic  im- 
portance, because  most  of  them  are  preventable.  The 
vital  causes  of  disease  which  are  known  to-day  are 
the  animal  and  vegetable  parasites  that  are  capable  of 
lodging  upon  the  surface  of  the  body  or  penetrating  into 
the  blood  and  tissues,  and  thus  give  rise  to  disordered 
function  either  by  producing  obstruction,  local  irritation, 
absorbing  large  quantities  of  nourishment  from  the  body, 
or  by  generating  highly  poisonous  secretion  and  excre- 
tion products  which  produce  disease  through  their  local 
or  general  action.  The  principal  animal  parasites  which 
produce  disease  are  the  various  forms  of  intestinal 
worms,  the  trichinella  spiralis,  the  filarise,  the  itch  mite, 
the  trypanosomata,  and  the  malarial  organisms.  The 
principal  vegetable  parasites  which  produce  disease  are 
the  different  forms  of  pathogenic  bacteria  and  the  plants 
of  somewhat  higher  order  which  produce  tinea  favosa  and 
other  skin  diseases. 

The  remote  causes  of  disease  operate  in  such  a  man- 
ner as  gradually  to  reduce  the  ph^'sical  powers  of  the 
body,  so  as  to  make  it  possible  for  the  vital  causes  to 
operate.  The  remote  causes  of  disease  may.  be  such  fac- 
tors as  undue  exposure  to  extremes  of  heat  and  cold, 
dampness  or  undue  dryness  of  the  atmosphere,  imdue 
exposure  to  bright  lights  or  strong  currents  of  air  may 
operate  in  this  manner,  prolonged  absence  of  sunlight, 
deticient   ventilation,   the   use  of  excessive  amounts  of 


CAUSES  OF  DISEASE.  x^ 

certain  kinds  of  food  and  drink,  the  continued  use  of  a 
diet  which  is  deficient  in  one  or  more  of  the  elements 
which  enter  into  the  composition  of  the  body,  maintain- 
ing the  body  in  abnormal  positions  for  a  long  time, 
undue  physical  or  mental  exertion,  deprivation  of  food 
and  sleep,  and  wearing  of  apparel  which  constricts  cer- 
tain portions  of  the  body. 

The  causes  of  disease  may  also  be  divided  into  the  pre- 
disposing and  the  exciting  causes.  The  predisposing 
causes  of  disease  are  the  various  conditions  which,  by 
their  influence  upon  the  body,  render  it  less  resistant  to 
the  invasion  of  pathogenic  bacteria,  or  otherwise  pre- 
dispose to  disordered  health.  The  conditions  which  have 
been  classed  as  remote  causes  of  disease  also  belong  in 
this  class,  but  besides  these  there  are  other  important 
conditions  which  predispose  to  disease,  such  as  the  age 
and  sex  of  a  person,  hereditary  influences,  race,  conjugal 
condition,  the  hygienic  condition  of  the  environment, 
the  density  of  the  population,  the  nature  of  the  occupa- 
tion, and  the  climate  of  the  locality.  Dr.  Farr  found 
that  the  mortality  increases  with  the  density  of  the 
population,  not  in  direct  proportion  to  the  density,  but 
as  its  sixth  root. 

The  exciting  causes  of  disease  are  the  specific  elements 
which  are  the  etiologic  factors  in  the  production  of  dis- 
ease. These  are  synonymous  with  the  immediate  causes 
of  disease  in  the  first  classification,  the  physical,  chemi- 
cal, and  vital  causes  of  disease. 

Predisposing  Causes  of  Disease. — i.  Age. — The  influ- 
ence of  age  is  a  most  important  factor  in  the  production 
of  disease.  The  age  groups  in  which  the  mortality  is 
greatest  are  to  be  found  in  the  periods  of  growth  and 
decline,  while  the  mortality  is  lowest  during  youth  and 
the  earlier  periods  of  adult  maturity.  The  highest  mor- 
tality occurs  among  children  imder  one  year  of  age, 
and  then  decreases  rapidly  until  we  reach  the  fifteenth 
year,  after  which  it  again  gradually  increases  until  we 
reach  the  period  between  sixt}'  and  seventy  years,  when 


20 


INTRODUCTION. 


it  again  decreases.  The  following  table,  taken  from  the 
annual  reports  of  the  Bureau  of  Health  of  the  city  of 
Philadelphia,  shows  "the  percentage  of  deaths  to  total 
mortahty  during  specified  periods  of  life,"  for  the  years 
1911  to  1915. 

The  Percentage  of  Deaths  and  Total  Mortality  at  Different  Periods 
OF  Life  in  Philadelphia  for  the  Years  191  i  to  1915,  Inclusive. 


Years. 

1911. 

191 

2. 

1913. 

1914. 

1915. 

Per 

Per 

Per 

Per 

Per 

Deaths. 

Cent.  • 

Deaths. 

Cent. 

Deaths. 

Cent. 

Deaths. 

Cent. 

Deaths. 

Cent. 

0-    1.  .  .  . 

4,630 

17-74 

4-1S5 

16.99 

4,64s 

18.00 

4,981 

14.78 

4,218 

16.04 

I-    2 .  .  .  . 

1. 139 

4.36 

825 

3-37 

974 

3.77 

1,021 

3-79 

937 

3-56 

2-    5 

i,iS7 

4-43 

863 

3.53 

926 

3.60 

935 

3-47 

722 

2.74 

S-  10 

S99 

2.29 

482 

1.97 

554 

2.15 

540 

2.04 

487 

1.8s 

10-  15.  .  .  . 

302 

i-iS 

282 

i-iS 

306 

1.19 

300 

1. 11 

312 

1. 18 

IS-  20. .  .  . 

S8S 

2.24 

558 

2.28 

496 

1.91 

500 

1.8s 

556 

2.11 

20-  30.  .  .  . 

I,8q2 

7.2s 

1,749 

7-iS 

1,872 

7.09 

1,806 

6.70 

1,813 

6.89 

30-  40 

2,580 

9.96 

2,276 

9-31 

2,388 

9.11 

2,301 

8.54 

2,343 

8.91 

40-  50 

2,650 

10.15 

2,716 

11.11 

2,725 

10.61 

2,971 

11.03 

2,895 

11.01 

SO-  60. .  .  . 

3.°72 

11.77 

3,082 

12.60 

3,170 

12.35 

3,339 

12.40 

3,430 

13.04 

60-  70.  .  .  . 

3.317 

12.33 

3,229 

13.16 

3,377 

13.15 

3,603 

13.84 

3,735 

14.20 

70-  80. .  .  . 

2,737 

10.48 

2,798 

11.44 

2,827 

11.20 

3,076 

11.42 

3,208 

12.20 

80-  90. .  .  . 

1,251 

4.78 

1,240 

5.07 

1,228 

4.76 

1,335 

4-05 

1,420 

5-40 

90-100. .  .  . 

175 

0.67 

180 

0.73 

171 

0.66 

200 

0.74 

199 

0.75 

lOO-IIO.  . .  . 

6 

0.02 

9 

0.03 

8 

0.03 

10 

0.03 

II 

0.04 

110-120. .  .  . 

1 

Total 

26,092 

24,445 

25,667 

26,918 

26,287 

A  comparison  of  the  number  of  deaths  and  percent- 
age of  deaths  in  persons  over  thirty  years  of  age  for  the 
years  1889  to  1894  and  1909  to  1913  shows  that  they 
are  both  higher  in  the  second  period  of  five  years  than 
in  the  first  period.  These  results  are  shown  in  a  more 
striking  manner  in  the  following  table : 


Year. 


2-    5-. 
5-  10.. 

10-  T-S- 
15-  20.. 
20-  30. . 
30-  40.. 
40-  50.. 
SO-  60.. 
60-  70. . 
70-  80. . 
80-  90 . . 
90-100. . 

lOO-IIO. . 

Total 


1889-1894. 


Per  cent. 
24.26 
6.18 
6.64 
3.69 
1.42 
2.62 
8.91 
8.93 
8.19 
8.09 
8.84 
7.66 
3.89 
0.61 
0.03 


99.86 


Per  cent. 

18.27 

4.17 

3-99 

2.18 

1.24 

2.38 

6.65 

9-59 

10.58 

11.81 

12.70 

10.65 

4-75 

0.66 

0.03 


99.22 


CA  USES  OF  DBA  TH. 


21 


The  high  infantile  mortality  is  due,  primarily,  to  the 
effects  of  faulty  nutrition,  owing  to  the  fact  that  so  many 
infants  must  be  fed  with  artificial  foods.  The  secondary 
causes  of  the  high  infant  mortality  are  the  acute  catar- 
rhal inflammations  of  the  gastro-intestinal  and  res- 
piratory tracts.  The  following  table  shows  the  rela- 
tive frequency  of  the  diseases  of  the  type  of  acute 
catarrhal  inflammations  of  the  gastro-intestinal  and  re- 
spiratory tracts  as  compared  with  the  death-rate  from  the 
acute  infectious  diseases,  of  diseases  of  the  nervous  sys- 
tem, and  the  deaths  from  all  causes  in  children  under 
one  year  of  age,  in  Philadelphia  during  the  years  191 1  to 
1915,  inclusive: 

DtnuNG  THE  Years  iqii  to  1915,  Inclusive. 


Deaths  under  one  year  from — 

igii. 

1912. 

1913- 

1914. 

1915- 

All  causes 

Diseases  of  gastro-intestinal  tract 

Diseases  of  the  respiratory  tract 

Acute  infectious  diseases 

4630 

1708 

829 

191 

95 

4155 

1390 

707 

106 

29 

4645 

1513 

783 

162 

114 

4981 
1612 

953 

208 

81 

4218 
1289 

743 
118 

Diseases  of  nervous  system 

"3 

The  principal  causes  of  death  in  persons  over  sixty  years 
of  age  are  shown  in  the  following  table,  as  indicated  by  the 
annual  reports  of  the  Bureau  of  Health  of  Philadelphia  for 
the  years  1911  to  1915,  inclusive.  The  table  also  shows 
the  total  number  of  deaths  for  the  same  years,  and  the 
deaths  from  all  causes  for  persons  over  sixty  years  of  age. 
Deaths  from  Certain  Causes  in  Persons  Over  Sixty  Years  of  Age. 


Total  deaths,  all  ages 

All  causes,  over  sixty  years 

Old  age 

Disease  of  the  heart 

Inflammation  of  lungs 

Apoplexy 

Paralysis 

Tuberculosis 

Cancer 

Bright's  disease 

Influenza 

Inflammation  of  bronchi 

Inflammation  of  stomach  and  bowels 

Inflammation  of  kidneys 

Debility 


I91I. 

1912. 

1913- 

1914. 

26,092 

24,445 

25,667 

26,918 

7,486 

7,457 

7,611 

8,224 

239 

245 

237 

234 

1,332 

1,570 

1,508 

1,778 

597 

544 

534 

724 

722 

631 

689 

714 

153 

124 

117 

100 

265 

204 

240 

226 

618 

652 

702 

660 

1,089 

1,139 

1,180 

1,225 

91 

54 

52 

84 

159 

163 

146 

187 

87 

77 

82 

95 

79 

85 

83 

lOI 

1915- 


26,287 

8,574 

206 

1,804 

541 

704 

75 

252 

679 

1,239 

183 
166 


22 


INTRODUCTION. 


In  the  period  of  life  now  under  discussion,  the  period 
of  decline,  diseases  dependent  upon  degenerations  of  the 
tissues  and  organs  are  the  most  prevalent,  especially  dis- 
eases of  the  vascular  system,  and  it  is  probable  that  the 
causes  of  those  deaths  described  by  the  vague  terms  "  old 
age"  and  "debility"  are  usually  dependent  upon 
degenerations  of  this  character. 

2.   Sex. — The  influence  of  sex  as  a  predisposing  cause 

of  disease  does  not   manifest  itself  to  any  extent  until 

after  puberty,  and  again  becomes  less  marked  after  the 

age  of  forty-five  to  fifty  years.     Certain  diseases  are  far 

more  prevalent  in  women  than  in  men,  such  as  hysteria 

and    allied  nervous  diseases;  while   epilepsy,  locomotor 

ataxia,  gout,  and  acute  diseases  of  the  respiratory  tract 

are   more  prevalent   in  men    than  in  women.     Women 

have  a  greater  average  longevity  than  men,  because  they 

are  exposed  less  and  are  not  engaged  in  such  dangerous 

occupations. 

Relative  Number  of  Deaths  Among  Males  and  Females  in  Philadel- 
phia, 1911  TO  1915. 


19 

[I. 

19 

[2. 

1913- 

1914. 

1915- 

Fe- 

Fe- 

Fe- 

Fe- 

Fe- 

Male. 

male. 

Male. 

male. 

Male. 

male. 

Male. 

male. 

Male. 

male. 

Epidemic  diseases . 

738 

719 

S70 

471 

689 

621 

617 

583 

564 

512 

General  diseases. . . 

2884 

268s 

2851 

25.53 

2872 

2576 

2990 

2624 

301 1 

2587 

Diseases    of    ner- 

vous sj'stem .... 

975 

947 

820 

863 

852 

930 

859 

846 

894 

922 

Diseases  of  circu- 

latory system. .  . 

1842 

1772 

2019 

1932 

1921 

1921 

2159 

2096 

2186 

2176 

Diseases  of  respir- 

atory system .  .  . 

1829 

1660 

1539 

1441 

1723 

1524 

2056 

1838 

201S 

1871 

Diseases  of  digest- 

ive system 

1789 

1556 

1579 

1430 

1661 

1487 

1731 

1513 

1514 

1401 

Diseases  of  genito- 

urinary system.. 

1329 

1418 

1386 

1293 

1449 

1381 

1480 

1408 

1419 

1405 

Puerperal  state .  .  . 

273 

240 

299 

313 

282 

Diseases  of  skin . .  . 

79 

70 

'84 

61 

82 

62 

114 

87 

'87 

82 

Diseases    of    loco- 

motor system.  .  . 

21 

10 

28 

22 

32 

12 

24 

15 

25 

IS 

Malformation .... 

59 

SO 

68 

43 

64 

45 

94 

70 

92 

80 

Early  infancy 

640 

508 

832 

s8o 

934 

666 

895 

692 

777 

621 

Old  age 

118s 

99 

166 

97 
1109 

7 

148 

482 

10 

8S 

1 107 

13 

153 

496 

10 

79 
1068 

155 

48s 

14 

63 
1099 

13 

143 

422 

9 

Violence 

488 
97 

Ill-defined  causes. . 

13 

Still-births 

1266 

86s 

1263 

885 

1172 

804 

1144 

78s 

1158 

813 

3.  Heredity. — Hereditary  influences  are  such  as  act 
from  within  the  body,  and  are,  therefore,  non-preventable. 
The  influence  of  heredity  is  shown  in  the  greater  prev- 
alence of  certain  diseases   in  one  family  than  another. 


CAUSES  OF  DISEASE.  23 

This  difference  is  brought  about  by  certain  constitutional 
conditions  which  are  "  transmitted  from  generation  to 
generation,  and  consists  in  a  lessened  capability  of  resist- 
ing unfavorable  influences  upon  the  system.  This  con- 
dition was  believed,  until  recently,  to  be  actually  a  trans- 
mission of  disease,  as,  for  instance,  in  tuberculosis. 
Since  the  discovery  of  the  specific  micro-organisms  of  a 
number  of  diseases  the  theory  of  direct  transmission 
has  been  discarded  to  a  great  extent.  At  the  present  time 
it  is  believed,  however,  that  a  predisposition  to  develop 
tuberculosis  is  transmitted,  and  that  in  these  subjects  the 
disease  is  far  more  readily  developed  than  in  those  with- 
out such  hereditary  predisposition.  In  like  manner  the 
transmission  of  a  predisposition  to  develop  other  consti- 
tutional diseases  is  recognized  to-day,  such  as  carcinoma, 
gout,  rheumatism,  diabetes,  disease  of  the  circulatory 
organs,  disease  of  the  nervous  system,  especially  insanity 
and  hysteria,  and  malformations. 

When  the  hereditary  infliiences  show  themselves  in  the 
same  sex  in  the  offspring  as  in  the  parent,  they  are  said 
to  be  homeomorphous,  and  when  they  show  themselves 
in  the  opposite  sex  they  are  said  to  be  heteromorphous. 

Hereditary  influences  are  intensified  by  the  intermar- 
riage of  near  relations,  because  these  influences  may  be 
present  in  both  parents. 

Connate  Conditioiis. — Connate  conditions  are  such  as 
are  born  into  a  person,  as  temperament,  idiosyncrasy, 
and  diathesis.  Temperament  refers  mainly  to  the  exter- 
nal appearance  of  the  person,  and  indicates  tendencies 
in  various  directions.  The  principal  temperaments  are 
the  sanguine,  the  lymphatic,  the  neurotic,  and  the 
melancholic  temperament.  Idiosyncrasy  has  reference 
to  special  liability  to  certain  affections,  as  hay  fever; 
or  peculiar  susceptibility  to  the  influence  of  drugs,  as 
ipecac,  opium,  quinin,  etc.,  or  to  certain  articles  of  diet,  as 
shell-fish,  berries,  etc.  Diathesis  has  reference  to  special 
tendencies  or  predisposition  to  particular  diseases,  as  ca- 
tarrhal affections ;  the  gouty  and  rheumatic  diathesis,  etc. ; 
and  indicates  a  weakness  in  a  particular  part  of  the  body. 


24  INTRODUCTION, 

The  late  Prof.  J.  G.  Richardson^  states  that  "persons 
of  a  sanguine  temperament  are  believed  to  be  especially 
liable  to  organic  diseases  of  the  heart,  to  aneurysms,  and  to 
the  bursting  of  blood-vessels  in  various  parts  of  the  body, 
so  that  they  should  especially  guard  against  articles  of 
food  and  habits  of  life  which  promote  the  formation  of 
an  excess  of  blood  in  the  system.  Individuals  of  lym- 
phatic temperament  seem  particularly  prone  to  scrofulous 
affections,  consumption,  dropsy,  and  skin  diseases;  those 
of  bilious  temperament,  to  diseases  of  the  liver,  stomach, 
and  intestines;  and  those  of  nervous  temperament  to 
palsy,  St.   Vitus's  dance,  epileptic  fits,  etc." 

4.  Race. — The  influence  of  race  as  a  predisposing  cause 
of  disease  is  quite  marked  for  some  races.  The  Jews,  as 
shown  in  a  special  study  of  this  race  by  Dr.  John  S. 
Billings,  are  more  liable  to  diseases  of  the  nervous  system, 
especially  diseases  of  the  spinal  cord,  to  diarrheal  diseases, 
diphtheria,  diseases  of  the  circulatory  organs,  the  urinary 
system,  bones  and  joints,  and  diseases  of  the  skin.  They 
are  less  liable  to  tuberculosis  than  their  neighbors. 

Detailed  studies  of  the  vital  statistics  of  Boston,  New 
York  and  Brooklyn,  Philadelphia,  Baltimore,  and  Wash- 
ington for  the  six  years  ending  May  31,  1890,  by  Dr. 
Billings,  have  shown  that  the  death-rate  among  children 
of  Irish  mothers  is  greater  from  consumption,  pneu- 
monia, inanition,  debility,  atrophy,  heart  disease  and 
dropsy,  and  from  typhoid  fever,  than  among  children  of 
German  mothers,  while  the  death-rate  among  children  ot 
German  mothers  is  markedly  greater  from  Bright' s  disease 
than  that  of  children  of  Irish  mothers.  A  large  part  of 
the  excessive  death-rate  among  children  of  Irish  mothers 
is  due  to  tubercular  diseases,  and  to  the  effects  of  alcohol, 
which  last  include  a  considerable  part  of  the  diseases  of 
the  nervous  system,  of  the  digestive  tract,  and  of  the 
urinary  organs  among  adults.  Cancer,  tumor,  and 
suicides  are  more  frequent  among  those  of  German 
parentage. 

The  higher  death-rate  among   the  colored   race   was 

'  Long  Life,  and  How  to  Reach  It. 


CAUSES  OF  DISEASE. 


35 


found  to  be  due  mainly  to  the  excessively  high  death- 
rate  among  children  of  that  race.  The  death-rate  from 
consumption,  pneumonia,  typhoid  fever,  diphtheria  and 
croup,  diarrheal  diseases  of  infants,  diseases  of  the  nerv- 
ous system,  and  heart  disease  and  dropsy,  was  found  to 
be  much  greater  among  the  colored  population  than 
among  whites.  The  negro  race  is  less  liable  to  yellow 
fever  and  to  malaria  than  the  white  race. 


Total  Deaths  Reported  in  Philadelphia  and  Rates  of  Tuberculosis 

AND  Syphilis  for  White  and  Colored  Population,  1903  to  1915. 

{Annual  Report  of  the  Bureau  of  Health,  igi5,  p.  76.) 


Population  esti- 
mated as  of 
July  ist. 

Total 
deaths. 

Rate  per 
1000  of 
popula- 
tion. 

Tuberculosis  of  lungs. 

Syphilis. 

Year. 

Deaths. 

Rate  per 
100,000  of 
population. 

Deaths. 

Rate  per 
100,000 

of  popu- 
lation. 

White: 

1903 

1904 

1905 

1906 

1907 

1908 

1909 

1910 

1911 

1912 

1913 

1914 

1915 

Colored : 

1903 

1904 

1905 

1906 

1907 

1908 

1909 

1910 

1911 

1912 

1913 

1914 

1915 

1,302,690 

1,326,371 
1,350,052 

1,373,733 
1,397,414 

1,421,096 
1,444,778 
1,468,459 
1,492,884 
1,517,309 

1,541,733 
1,566,158 

1,590,583 

70,724 
72,897 
75,070 
77,243 
79,416 

81,589 
83,762 

85,935 
87,364 
88,793 

90,223 
91,652 
93,081 

24,510 
24,478 
23,228 

25,337 
25,182 

23,697 
22,914 
24,740 
24,251 
22,805 

23,405 
24,624 

23,952 

1,437 
1,493 
1,579 
2,431 
2,294 

2,229 
2,115 
2,305 
2,025 
1,708 

2,207 
2,294 
23,35 

18.81 

18.45 
17.21 
18.44 
18.02 

16.68 
15.86 
16.85 
16.24 
15-03 

15.18 
15-72 
15.06 

20.32 
20.48 
21.03 

31-47 
28.89 

27-32 
25-25 
26.82 
23.18 
19.24 

24.46 
25.02 
25.09 

2760 
2771 
2526 
2804 
2776 

2638 
2485 
2548 
2642 
2416 

2278 
2289 
2318 

293 
346 
312 
357 
381 

430 
378 
459 
416 

318 

414 
395 
436 

211.87 
208.92 
187.10 
204.12 
198.65 

185-63 
172.00 
173-52 
176.97 
159-23 

147-76 
146.15 
145-73 

414.29 

474-64 
415.61 
462.18 
479-75 

527-03 
451.28 
534-12 
476-17 
358-14 

458.86 
430.98 
468.41 

30 
68 
49 
87 
78 

66 
69 
84 
96 
102 

108 
100 

lOI 

3 
3 

14 
17 
19 

20 
22 
18 
26 
23 

21 
41 

44 

2.30 
5-13 
3-63 
6-33 

5-58 

4.64 
4-78 
5-72 

6-43 
6.72 

7.01 
6-39 
6-35 

4-24 

4.12 

18.65 

22.01 

23-92 

24-51 
26.26 

20.95 
29.76 
25.90 

23.28 

44-73 
47.27 

26 


IN  TROD  UCTION. 


5.  Conjugal  Co7idition. — The  influence  of  conjugal 
conditions  upon  death-rates  is  manifest  from  the  follow- 
ing studies  made  in  Baltimore  and  Washington  for  the 
Eleventh  Census  : 

Death-rates. 


Baltimore. 

Washington. 

Conjugal 
condition. 

White. 

Colored. 

White. 

Colored. 

Male. 

Female. 

Male. 

Female. 

Male. 

Female. 

Male. 

Female. 

Single    .... 
Married     .    .    . 
Widowed .    .    . 

9.19 

8.98 

26.90 

6.53 

9.76 

12.10 

13-75 
13-49 
12.02 

13.20 
16.31 
14.36 

10.07 

9.06 

40.17 

6.44 

9-56 

13-65 

19.98 
16.60 
50-51 

14.50 
16.70 
15.12 

The  lower  death-rate  among  the  married  than  among 
either  single  or  widowed  is  probably  due  to  the  better 
home  care  these  individuals  have,  and  also  to  the  fact 
that  they  lead  more  regular  lives.  The  extremely  high 
death-rate  among  widowed  males  is,  no  doubt,  traceable 
to  the  influences  exerted  by  the  destruction  of  the  home 
and  the  effects  entailed  by  this  loss.  Of  course,  the  age 
factor  also  exerts  an  important  influence  upon  these 
individuals. 

6.  Hygienic  Conditio7is  of  Environment. — The  influ- 
ence of  overcrowding  and  general  unhealthy  surround- 
ings, along  with  privation  and  want,  are  most  important 
as  predisposing  causes  of  disease.  It  is  somewhat  difficult 
to  obtain  statistical  evidence  of  the  unfavorable  influence 
upon  health  of  the  general  hygienic  conditions  of  the  sur- 
roundings, yet  the  following  table,  based  upon  the 
special  Census  Report  for  Philadelphia  in  1890,- shows 
this  effect  fairly  well,  especially  with  regard  to  the  death- 
rate  from  consumption.  It  will  be  seen  that,  in  general, 
in  those  wards  in  which  the  number  of  persons  to  a 
dwelling  and  the  number  of  families  to  a  dwelling  are 
greater  than  the  average  for  the  entire  city  the  death- 
rate  from  consumption  is  also  above  the  average,  and  that, 
in  general,  in  those  wards  in  which  the  number  of  per- 
sons to  a  dwelling  and  the  number  of  families  to  a  dwell- 
ing are  below  the  average  the  death-rate  from  consump- 
tion is  also  below  the  average  for  the  entire  city. 


CAUSES  OF  DISEASE. 


27 


Aside  from  the  influence  of  overcrowding,  there  are 

other  conditions  of  environment  that  may  be  classed  as 
predisposing  causes  of  disease.     The  most  prominent  of 

Philadelphia^  i8go.      Census  Report. 


Persons  to 

Q 

Death-rate 

Number  of 

s; 

per  1000 
pop. 

Death-rate  per 
100,000  pop. 

families  to 
dwelling. 

Population. 

A 

^ 

Dwelling. 

Acre. 

All  causes. 

Consumption. 

Acres. 

5 

7.48 

88.94 

25.67 

498.02 

1.43 

16,987 

205 

6 

6.81 

44.68 

24.30 

418.46 

1.38 

8,712 

205 

II 

6.71 

95-95 

28.31 

330.86 

1.38 

12,953 

135 

4 

6.53 

141.56 

29.98 

441.11 

1.24 

20,384 

147 

9 

6-45 

38.25 

25.10 

364.04 

1. 10 

9.791 

256 

8 

6.41 

61.27 

24.26 

332.28 

1.08 

16,971 

278 

7 

6.35 

110.14 

24.30 

408.91 

1.20 

30,179 

281 

10 

6.33 

98.69 

19.88 

278.12 

1.07 

21,514 

230 

27 

6.30 

4-51 

31-91 

504.81 

1.05 

32,905 

^  7,475 

3 

6.19 

164.67 

23.91 

7>^1>-2>1> 

1.23 

19,925 

122 

15 

6.09 

99.82 

20.08 

288.71 

1. 10 

52,705 

671 

12 

6.08 

114.27 

21.57 

314.16 

1. 21 

14,170 

124 

2 

6.06 

115.62 

23.93 

316.35 

1.23 

31,563 

283 

13 

5-90 

109.96 

20.67 

260.98 

1. 16 

17,923 

163 

17 

5-82 

I22'93 

28.89 

355-83 

1. 19 

19,546 

161 

34 

5.66 

(Includ 

ed  in  24th 

ward). 

1.04 

14 

5.61 

136.43 

21.47 

320.62 

I. II 

20,737 

152 

16 

5.60 

94.93 

28.04 

311. 21 

1. 21 

17,087 

180 

29 

5.56 

87.20 

20.19 

293.26 

1.06 

54,759 

896 

20 

5-55 

94.84 

20.77 

303-14 

1. 14 

44,480 

469 

30 

5-55 

92.21 

22.12 

349-35 

1.09 

30,614 

332 

19 

546 

126.53 

2373 

310-44 

I. II 

55,545 

447 

24 

5-41 

14.07 

17.95 

269.24 

1.05 

66,277 

6,224 

22 

5-40 

3.68 

17.77 

241.27 

1.03 

45,329 

12,738 

21 

5-35 

6.44 

19.45 

242.86 

1.05 

26,900 

4,563 

26 

5-32 

13.18 

19.48 

238.37 

1.05 

62,138 

4,788 

25 

525 

14.41 

24.29 

271.55 

1.06 

35,945 

2,641 

33 

5-23 

12.23 

13.07 

143.47 

1.06 

33,171 

2,844 

31 

5-17 

7231 

21.46 

284.92 

1.03 

32,974 

456 

18 

5-16 

71-83 

24.42 

304.57 

1.09 

29,164 

416 

I 

5-15 

15-34 

22.08 

275.54 

105 

53,882 

3,526 

28 

5-15 

14.62 

15.56 

185.73 

1.05 

■    46,390 

3,542 

23 

5.06 

1.30 

18.50 

219.39 

1.02 

35,294 

27,339 

32 

5-04 

118.77 

14.61 

192.32 

1.03 

30,050 

518 

City 

5.60 

1332 

21.54 

297.87 

1. 10 

1,046,964 

82,807 

these  factors  are  the  nature  of  the  water-supply  and  the 
character  of  the  drainage.  The  relation  of  these  factors 
to  the  public  health  will  be  considered  in  detail  in  special 
chapters.     Dampness  of  the  soil  of  a  locality  is  also  an 

1  Hospital  and  Almshouse. 


28  INTRODUCTION. 

important  factor,  and  its  influence  in  relation  to  con- 
sumption has  been  carefully  investigated  by  Dr.  Bow- 
ditch,  of  Boston,  and  Dr.  Buchanan,  of  London.  Their 
investigations  have  shown  that  the  death-rate  from  con- 
sumption is  in  proportion  to  the  dampness  of  the  soil. 
Dampness  of  soil  is  also  an  important  predisposing  factor 
in  the  production  of  many  other  diseases,  such  as  mala- 
ria, rheumatism,  and  catarrhal  affections. 

The  influence  of  the  nature  of  the  occupation,  and  of 
the  climate  of  a  locality,  as  predisposing  factors  of  dis- 
ease will  be  discussed  in  detail  in  special  chapters  on 
these  subjects. 

Sanitary  science  refers  to  the  investigation  of  the 
causes  of  disease  and  the  means  of  avoiding  or  destroying 
them.  It  is  not  a  specific  department  or  separate  branch 
of  science,  but  is  implied,  in  part,  in  a  number  of 
sciences,  as  chemistry,  biology,  physics,  pathology,  statis- 
tics, etc. 

The  term  sanitary  means  conducive  to  the  preservation 
of,  and  the  term  sanitary  conducive  to  the  restoration  of, 
health.  The  sanitary  condition  of  a  place  has  reference 
to  the  presence  or  absence  of  the  specific  causes  of  disease. 
There  is  no  such  thing  as  bad  hygiene:  A  place  is  either 
in  hygienic  condition  or  it  is  in  an  unhealthful  condition. 

Hygiene  aims  to  discover  the  causes  of  all  diseases 
known,  and  the  best  means  of  removing  those  causes  or 
rendering  them  inoperative.  It  takes  for  granted  a 
knowledge  of  the  normal  functions  of  the  human  organ- 
ism, and  seeks  to  discover  the  reasons  for  perverted 
action  of  a  part  or  the  whole  of  the  organism.  It  involves 
a  thorough  knowledge  of  the  normal  conditions  of  man's 
environment  as  well  as  the  various  factors  which  tend  to 
render  that  environment  abnormal.  It  demands  a 
thorough  knowledge  of  the  chemical  and  physical  charac- 
ter of  man's  food-supply  and  those  changes  to  which  it  is 
liable  that  tend  to  injure  his  health  and  produce  disease. 
It  aims  to  keep  persons  in  perfect  health,  to  train  men  to 
be  strong  both  mentally  and  physically.  It  also  involves 
a  knowledge  of  the  physical  and  geological  nature  of  the 


HYGIENE.  29 

surface  of  the  earth,  and  the  manner  in  which  these  con- 
ditions, in  different  localities,  influence  the  healthfulness 
of  human  habitations.  It  comprises  a  knowledge  of  all 
the  various  human  ocupations,  and  the  manner  in  which 
these  may  be  conducted  so  as  to  be  free  from  danger  to 
health  or  how  to  render  them  least  objectionable. 

Hygiene  may  be  subdivided  into  several  departments 
relating  to  the  scope  of  its  application,  as  public  or 
general,  military,  naval,  personal,  municipal,  school, 
and  industrial  hygiene.  Public  hygiene  takes  cogni- 
zance of  factors  which  affect  the  general  public,  such  as 
nuisances  of  different  kinds:  Foul  odors,  noxious  gases 
or  dust  evolved  in  certain  manufacturing  processes,  and 
loud  noises.  Nuisances  are  generally  such  conditions 
which  aggravate  existing  disease  rather  than  produce 
disease.  Military,  naval,  personal,  school,  and  indus- 
trial hygiene  will  be  treated  more  or  less  generally 
in  special  chapters.  Municipal  hygiene  has  reference 
to  those  conditions  which  affect  the  general  health  of 
a  community  that  fall  directly  under  the  control  of 
municipal  governments,  such  as  the  influence  of  impure 
water-supplies  and  imperfect  drainage  upon  the  general 
health;  the  influence  of  overcrowding  in  the  habita- 
tions of  the  poor;  the  cleansing  of  city  streets  and  the 
removal  and  satisfactory  disposal  of  refuse  matters  ;  the 
regulation  of  the  isolation  and  care  of  those  affected  with 
infectious  diseases,  and  the  proper  disposal  of  the  dead. 

Development  of  Hygiene. — Modern  hygiene  has  been 
gradually  evolved  out  of  the  observations  and  discoveries 
of  many  men  prominent  in  philanthropic  work,  in  medi- 
cine, and  in  science.  Among  the  prominent  observations 
and  discoveries  made  during  the  eighteenth  centiiry 
which  have  been  most  instrumental  in  the  development 
of  hygiene  may  be  mentioned  the  discovery  of  Sir 
George  Baker  with  regard  to  the  production  of  lead- 
poisoning  by  cider  stored  in  leaden  vessels;  the  observa- 
tions of  John  Howard  with  regard  to  the  baneful  influence 
of  foul  air  and  overcrowding  and  unheal thfulness  of  the 
surroundings  upon  the  health  of  the  occupants  of  prisons, 


30  INTRODUCTION. 

poor-houses,  and  other  habitations,  and  their  relation  to 
typhus  fever  ;  the  demonstration  by  Captain  James  Cook, 
in  his  voyage  around  the  world,  that  scurvy  was  a  pre- 
ventable disease  which  was  due  to  the  nature  of  the  diet; 
and  Sir  Edward  Jenner's  discovery  of  inoculation  as  a 
preventative  of  small-pox.  During  the  nineteenth  cen- 
tury the  movements  and  discoveries  which  stand  out 
most  prominently  are  the  work  of  Dr.  Thomas  South- 
wood  Smith  and  The  Sanitary  Committee  in  demonstrat- 
ing the  factors  which  are  instrumental  in  influencing 
the  health  of  towns,  such  as  the  accumulation  of  filth 
about  premises,  absence  of  sewers,  and  consequently 
the  pollution  of  water-supplies,  and  the  influence  of  in- 
sufficient air-supply  and  overcrowding  upon  the  general 
health;  the  labors  of  Edwin  Chadwick  in  organizing  the 
first  board  of  health  in  England;  the  work  of  Dr.  William 
Farr,  Registrar-General  of  England,  in  securing  the  regis- 
tration of  the  cause  of  death  in  the  health  reports;  the 
labors  of  Dr.  E.  A.  Parkes  in  demonstrating  the  evil  effects 
of  defective  drainage  and  the  accumulation  of  filth  upon 
the  public  health,  and  in  securing  the  passage  of  various 
sanitary  acts  from  1848  to  1857;  the  work  of  Dr.  John 
Simon,  of  London,  and  his  able  staff  of  medical  inspec- 
tors with  regard  to  the  material  causes  of  disease,  and  the 
legislation  which  was  based  upon  these  investigations;  the 
studies  of  Dr.  C.  A.  Louis,  of  Paris,  upon  typhoid,  typhus, 
and  relapsing  fevers,  and  the  differentiation  between  these, 
as  well  as  similar  studies  made  at  the  same  time  by  Dr. 
William  W.  Gerhard,  of  Philadelphia;  the  studies  of  Dr. 
Henry  I.  Bowditch,  of  Boston,  and  those  of  Dr.  George 
Buchanan,  of  London,  upon  the  influence  of  dampness 
of  the  soil  upon  the  prevalence  of  consumption;  the 
studies  of  Louis  Pasteur  upon  the  causes  of  fermentation 
and  the  etiologic  relation  of  micro-organisms  to  disease, 
as  well  as  his  discoveries  with  regard  to  the  prevention 
and  treatment  of  these  diseases  ;  the  studies  of  Sir  Joseph 
Lister  witli  regard  to  the  prevention  of  suppuration  in 
wounds,  which  have  been  the  starting-point  of  modern 


HYGIENE.  31 

antiseptic  and  aseptic  surgery ;  the  work  of  von  Petten- 
kofer  in  introducing  new  methods  of  chemical  research 
upon  air,  water,  and  food,  and  his  studies  upon  the  in- 
fluence of  soil-moisture  upon  the  prevalence  of  typhoid 
fever  and  cholera;  and  the  discoveries  of  Dr.  Robert 
Koch  of  the  specific  micro-organisms  of  some  of  the  in- 
fectious diseases,  and  in  perfecting  methods  of  bacterio- 
logic  investigation. 

Since  we  have  become  acquainted  with  the  direct  causa- 
tive factors  of  many  of  the  contagious  diseases,  we  have 
developed  preventive  measures  that  were  impossible  before 
the  causes  of  disease  were  known.     The  discovery  of  the 
influence  of  different   chemical  and  physical  agents,   in 
destroying  the  bacteria  outside  the  body,  has  been  of  very 
great  value  in  limiting^  the  dissemination  of  disease.     The 
discovery  of  immune  serums,  especially  the  antitoxins  of 
diphtheria  and  tetanus,  has  been  of  great  service  in  limit- 
ing the  dissemination  of  disease  when  employed  both  as 
prophylactic  and  curative  agents.     The  introduction  of 
the  methods  of  inoculation  of  attenuated  living  and  espe- 
cially the  injection  of  dead  cultures  of  bacteria  for  the 
prevention  and  ciure  of  bacterial  diseases  has  been  an 
important   step   forward,   especially  in  the  control  of 
cholera,  plague,  and  typhoid  fever.     The  discovery  of 
the  influence  of  certain  suctorial  insects  in  the  dissemi- 
nation of  disease,  as  the  several  species  of  mosquitoes 
in  the  dissemination  of  malarial  fevers,  yellow  fever,  of 
filariasis,  and  of  dengue;  the  role  played  by  the  rat  flea 
in  the  dissemination  of  plague,  the  tsetse  fly  in  the  dis- 
semination of  sleeping  sickness,  the  body  louse  in  the 
dissemination  of  typhus  fever,  and  the  tick  in    the  dis- 
semination of  African   "tick"   fever,   are  some  of  the 
more  important  of  this  class  of  diseases  that  can  now 
be  controlled  more  intelligently  since  the  mode  of  dis- 
semination is  known.    The  introduction  of  modern  meth- 
ods of  water  purification  and  sewage  disposal  are  also 
important  factors  in  Hmiting  the  dissemination  of  disease 
by  means  that  were  unknown  a  quarter  of  a  century  ago. 


CHAPTER    I. 
AIR. 

Nature  and  Composition  of  the  Atmosphere. — 

Atmospheric  air  consists  of  a  mechanical  mixture  of 
gases,  the  relative  proportions  of  which  are  fairly  con-, 
stant  in  all  parts  of  the  world.  It  is  colorless,  odorless, 
transparent,  and  is,  therefore,  invisible  and  imperceptible 
when  quiescent. '  It  is  only  when  it  is  itself  in  a  state  of 
motion,  or  when  our  bodies  are  in  rapid  motion,  that  we 
note  its  presence  through  the  resistance  which  it  mani- 
fests. It  also  possesses  weight,  and  consequently  exerts 
pressure.  At  the  sea-level,  when  the  temperature  is 
o°  C,  the  normal  pressure  of  the  atmosphere  is  sufficient 
to  support  a  column  of  mercury  760  millimeters  in  height, 
and  amounts  to  1033  grams  on  every  square  centimeter 
of  surface.  The  pressure  of  the  atmosphere  decreases  as 
we  rise  above  the  level  of  the  sea,  and  increases  as  we 
descend  below  its  level. 

The  several  gases  composing  the  atmosphere  are  not 
in  chemical  combination  with  each  other,  but  exist  as  a 
more  or  less  homogeneous  mixture.  The  principal  gases 
in  the  mixture  are:  Nitrogen  in  the  proportion  of  78.20 
parts,  by  volume;  oxygen,  20.76  parts;  argon,  i  part; 
carbon  dioxid,  0.04  part;  a  trace  of  ammonia;  traces  of 
nitrous  and  nitric  acids;  small  amounts  of  ozone;  vary- 
ino-  proportions  of  aqueous  vapor;  and  traces  of  several  re- 
cently discovered  constituents :  neon,  erythron, and  krypton. 

The  proportion  of  nitrogen  in  natural  air  varies  only 
within  extremely  narrow  limits.  It  is  an  indifferent  gas, 
and  seems  to  serve  principally  as  a  diluent  for  the  oxygen 
in  the  air.  So  far  as  known,  the  only  biologic  signifi- 
cance of  nitrogen  is  its  absorption  by  plants  of  the  order 
LegiiminoscE  when  growing  in  symbiosis  with  certain 
micro-organisms  which  find  lodgement  on  the  roots  of 

32 


NATURE  AND  COMPOSITION  OF  ATMOSPHERE.    33 

these  plants,  and  where  they  cause  the  formation  of  the 
so-called  root-tubercles.  Indirectly  nitrogen  is  also  stored 
in  the  soil  by  certain  soil  bacteria  and  in  turn  vegetation 
obtains  this  nitrogen  as  food  in  the  form  of  nitrates  and 
ammonia.  Argon,  neon,  erythron,  and  krypton  are  like- 
wise inert  gases  so  far  as  known  at  the  present  time. 

The  proportion  of  oxygen  in  the  air  varies  within 
somewhat  wider  limits  than  that  of  nitrogen,  but,  under 
natural  conditions,  it  is  fairly  constant,  because  any 
slight  decrease  in  its  proportion  in  circumscribed  locali- 
ties is  readily  corrected  through  the  action  of  the  princi- 
ple of  diffusion. 

The  proportion  of  carbon  dioxid  varies  usually  between 
0.03  and  0.05  part  per  100,  but  it  is  subject  to  still  greater 
fluctuations  at  different  points  on  the  earth's  surface,  and 
at  different  seasons  of  the  year.  The  fluctuations  in  the 
proportion  of  carbon  dioxid  are  brought  about  by  the 
active  decomposition  and  putrefaction  of  organic  matters 
through  the  agency  of  bacteria,  and  through  the  com- 
bustion of  combustible  materials  in  manufacturing 
centres.  The  overproduction  of  carbon  dioxid  at  any 
point  tends  to  become  equalized  through  the  operation  of 
the  principle  of  diffusion  and  the  movements  of  the 
atmosphere.  The  proportion  of  carbon  dioxid  is,  gener- 
ally, greatest  at  the  surface  of  the  earth,  and  decreases  as 
the  elevation  increases.  It  is  least  in  winter  and  great- 
est in  autumn  ;  less  during  the  day  than  at  night ;  less  on 
the  seacoast  than  inland;  and  less  on  wind}-  da}"s  than  on 
calm  days.  It  is  decidedly  diminished  by  rain,  slightly 
so  by  snow,  and  slightly  increased  during  fogg}'  weather. 

The  relative  proportions  of  oxygen  and  carbon  dioxid 
are  maintained  through  the  combined  action  of  the  vege- 
table and  animal  world.  The  animal  kingdom  absorbs 
oxygen  and  gives  off  carbon  dioxid  in  return  as  the 
result  of  tissue  metabolism.  On  the  other  hand,  tho.se 
members  of  the  vegetable  kingdom  which  pos.se.ss 
chlorophyl  in  their  organism  have  the  property  of  ab- 
sorbing carbon  dioxid  from  the  air,  assimilating  the  car- 
bon and  giving  off  the  oxygen  in  return.  This  most 
3 


34 


AIR. 


interesting  cycle  is  an  important  factor  in  the  maintenance 
of  the  relative  proportions  of  these  two  gases  in  the  air. 

The  proportion  of  aqneous  vapor  in  air  varies  with  the 
temperature — the  average  amount  being  about  i  per  cent. 
The  amount  of  moisture  in  the  air  may  vary  from  less  than 
o.  I  per  cent,  to  as  much  as  4  per  cent.  The  higher  the 
temperature,  the  greater  the  amount  of  aqueous  vapor 
that  is  taken  up  by  air.  The  proportion  which  is  most 
agreeable  to  the  majority  of  persons,  and  therefore  the 
most  suitable  for  health,  is  about  50  per  cent,  of  satura- 
tion at  any  given  temperature. 

Ozone — condensed  or  allotropic  oxygen — is  present  in 
variable  amounts  in  different  places  on  the  earth's  sur- 
face. The  average  amount  present  is  i  milligram  per 
100  cubic  meters  of  air;  the  maximum  amount  being 
about  3.5  milligrams.  This  gas  is  usually  absent  from 
the  air  of  cities  and  the  air  which  has  passed  through 
localities  that  are  thickly  populated.  It  is  found  in 
the  atmosphere  over  fields  covered  with  vegetation,  over 
forests,  and  over  the  ocean.  Ozone  is  an  active  oxidizing 
agent,  and  the  air  of  cities  is  rich  in  oxidizable  organic 
matter  which  absorbs  it,  consequently  it  is  absent  from 
the  air  of  cities.  •  Generally  speaking,  the  healthiest  parts 
of  towns  are  those  receiving  the  purer  and  fresher  air, 
containing  ozone,  coming  from  cultivated  fields,  forests, 
or  the  ocean. 

The  amounts  of  ammonia,  nitrous  and  nitric  acids, 
found  in  ordinary  atmospheric  air  are  insufficient  to  have 
any  biologic  significance.  They  result  principally  from 
putrefaction  and  from  various  manufacturing  industries. 

The  atmosphere  forms  a  gaseous  envelope  which  sur- 
rounds the  earth,  reaching  a  height  of  from  320  to  350 
kilometers  above  the  earth's  surface,  and  penetrating 
into  the  porous  soil,  into  caves  and  mines,  and  into  the 
ocean  to  a  great  depth. 

Temperature  of  the  Air. — There  are  three  main  fac- 
tors that  influence  the  temperature  of  the  air  of  any 
place,  viz.,  latitude,  altitude,  and  the  relative  proximity 
of  large  bodies  of  water.     The  temperature  is  greatest 


PRESSURE  OF  THE  A  TMOSPHERE.  35 

near  the  equator  and  decreases  proportionately  with  the 
distance  traversed  in  passing-  from  the  equator  to  the 
north  or  south  pole.  The  temperature  is  also  higher  at 
the  level  of  the  sea  than  on  the  top  of  a  mountain  in  the 
same  latitude.  Places  near  the  seacoast  also  have  a  more 
equable  climate  than  those  in  the  interior.  The  other 
factors  which  influence  the  temperature  of  a  Ipcality  are: 
The  conformation  of  the  earth's  surface;  the  nature  of 
the  soil;  the  character  and  extent  of  the  soil-covering; 
and  the  direction  of  the  prevailing  winds.  Owing  to  the 
high  specific  heat  of  water  (about  five  times  that  of  earth 
and  rocks)  the  ocean  absorbs  heat  slowly  and  gives  it 
off  slowly,  and,  therefore,  it  acts  as  a  reservoir  of  the 
heat,  absorbing  it  during  the  day  and  giving  it  off"  during 
the  night,  also  absorbing  it  during  the  summer  and  giving 
it  off"  during  the  winter,  thus  lessening  the  heat  of  summer 
as  well  as  the  cold  of  winter  for  places  along  the  seacoast. 
Pressure  of  the  Atmosphere. — The  average  pressure 
of  the  atmosphere  varies  according  to  the  altitude  of  the 
locality,  and  also  in  the  same  locality  at  different  times. 
At  the  sea-level  this  average  pressure  amounts  to  a  little 
over  a  kilogram  per  square  centimeter,  and  is  sufficient  to 
support  a  column  of  mercury  760  millimeters  in  height; 
hence  the  total  weight  supported  by  an  average  man  is 
about  18,000  kilograms.  This  weight  or  pressure  is  con- 
siderable, but  it  is  unnoticed  because  it  is  equalized  by  the 
internal  pressure  of  our  bodies,  which  adapt  themselves 
to  the  normal  fluctuations  in  the  atmospheric  pressure. 
Variations  in  the  atmospheric  pressure  are  measured  by 
means  of  barometers.  The  mercurial  barometer  is  usually 
employed  in  making  these  observations  (Fig.  i).  Marked 
deviations  from  the  normal  atmospheric  pressure,  such  as 
are  found  in  exceedingly  high  altitudes,  in  balloon  ascen- 
sions to  great  heights,  or  when  descending  to  great  depths 
in  mines,  or  working  in  tunnels,  are  manifested  by  effects 
which  are  referable  to  the  increased  or  decreased  tension 
of  the  atmosphere.  Rarefied  air  as  found  at  great  heights 
induces  a  condition  known  as  mountain  sickness  or  bal- 
loon  sickness,    and   consists    in    increased  heart  action, 


36 


AIR. 


more  rapid  respiration,  headache,  followed  by  graver 
symptoms  as  the  rarefaction  increases,  such 
as  vomiting  of  food,  bile,  and  blood,  with 
great  pain  in  the  stomach,  followed  by 
death.  There  are  frequently  minute 
hemorrhages  into  the  spinal  cord  as  the 
result  of  inspiring  rarefied  air.  The  in- 
sufficient supply  of  oxygen  in  the  rarefied 
air  is  perhaps  the  principal  cause  of  the 
symptoms  manifested. 

,The  effects  of  passing  from  the  normal 
atmospheric  pressure  to  a  greater  pressure, 
as  in  diving-bells,  in  tunnels  under  rivers, 
are  different  from  those  seen  on  ascending 
to  a  great  height,  and  here  the  effects  are 
due  to  the  increased  pressure  upon  the 
body.  Bvery  lo  meters  of  water  adds 
the  pressure  of  i  atmosphere — i  kilogram 
per  square  centimeter  of  body  surface. 
The  increased  pressure  causes  the  sudden 
liberation  of  gases  in  the  tissues  and 
blood,  where  they  interfere  with  the  cir- 
culation and  stop  the  heart.  The  differ- 
ence in  pressure  on  the  tympanic  cavity 
causes  vertigo  and  pain  in  the  ear,  and  if 
the  difference  in  pressure  is  great  the  drum 
of  the  ear  may  be  ruptured  when  the  Eus- 
tachian tube  is  occluded.  Ordinarily  the 
difference  in  pressure  is  equalized  by  the 
act  of  swallowing.  On  coming  out  of  a 
caisson  the  reverse  in  internal  and  exter- 
nal pressure  takes  place.  This  is  also  re- 
lieved in  the  same  manner.  Man  can  work 
at  a  kilometer  below  the  sea-level  without 
injury,  and  he  can  travel  to  a  height  of  5 
or  6  kilometers  without  being  affected  by 

Fic;.  I.— Mercurial  barometer:  a,  cistern  containinor  the  mercury;  b,  screw 
in  movable  bottom  of  cistern,  to  raise  or  lower  the  mercury  to  the  "  fiducial " 
point ;   c,  the  vernier ;  d,  the  thermometer. 


DISTRIBUTION  OF  A  TMOSPHERIC  PRESSURE.     37 

the  decrease  of  pressure.  When  the  pressure  is  suddenly- 
increased  or  decreased  beyond  these  points  the  effects  are 
manifested.  The  more  slowly  the  change  is  brought 
about,  and  the  smaller  the  amount  of  exertion  accom- 
panying the  change  of  pressure,  the  less  the  effect 
produced.  Great  variations  from  the  normal  atmos- 
pheric pressure  are  highly  injurious  to  all  persons  suf- 
fering from  organic  disease  of  the  heart  and  lungs,  and 
to  those  suffering  from  an  atheromatous  condition  of  the 
arteries,  because  this  condition  prevents  the  arteries  from 
readily  adjusting  themselves  to  the  altered  pressure,  thus 
leading  to  hemorrhages.  In  coming  out  of  the  caisson 
the  change  in  pressure  must  be  brought  about  slowly. 
The  too  rapid  change  induces  spinal  hemorrhage.  At 
least  six  to  ten  minutes  should  be  allowed  for  each 
additional  atmosphere  of  pressure  to  make  the  change 
safely.  The  air-locks,  where  the  change  of  pressure  is 
made,  should  be  at  the  top  of  the  shaft,  and  not  at  the 
bottom,  so  that  the  men  are  not  obliged  to  climb  the 
ladder  when  they  come  into  the  ordinary  pressure. 

Distribution  of  Atmospheric  Pressure. — The  ba- 
rometer is  high  (i)  when  the  air  is  very  cold,  for  then 
the  lower  strata  are  denser  and  more  contracted  than 
when  it  is  warm.  The  contraction  causes  the  upper 
layers  to  sink  down,  bringing  a  greater  number  of  air- 
particles — that  is,  a  greater  mass  of  air — into  the  column, 
so  that  the  pressure  at  its  base  is  greater;  (2)  when  the 
air  is  dry,  for  then  it  is  denser  than  when  it  is  moist; 
(3)  when  in  any  way  an  upper  current  sets  in  toward  a 
given  area,  for  this  compresses  the  strata  underneath. 

Conversely,  the  barometer  is  low  (i)  when  the  lower 
strata  are  heated,  causing  the  surfaces  of  equal  pressure 
to  rise,  and  the  upper  layers  to  slide  off,  consequently 
the  mass  of  air  pressing  on  the  area  below  is  reduced  ; 
(2)  when  the  air  is  damp,  for  as  the  density  of  aqueous 
vapor  at  0°  C.  temperature  and  760  millimeters  pressure 
is  0.7721,  air  being  i,  the  mixture  is  lighter  the  more 
vapor  it  contains,   and  consequently  damp  air  does  not 


38  AIR. 

press  as  heavily  as  dry  air  on  the  unit  of  area  below;  (3) 
when  the  air,  from  any  cause,  has  an  upward  movement, 
for  this,  of  course,  acts  in  the  same  manner  as  when  the 
lower  strata  are  heated. 

Humidity  of  the  Atmosphere. — Atmospheric  air  con- 
tains more  or  less  watery  vapor  at  all  times.  The  quan- 
tity of  water  present  in  the  air,  at  any  time  and  place,  is 


Fig.  2. — Daniell's  hygrometer :  a,  bulb  surrounded  with  cotton  cloth ;  b,  ther- 
mometer;  c,  bulb  containing  thermometer. 

dependent — {a)  upon  the  possibility  of  the  air  obtaining 
moisture  from  the  surface  of  a  large  body  of  water ;  {b) 
upon  the  rate  of  diffusion  of  the  moist  air  of  the  locality 
and  its  replacement  by  drier  air ;  and  {c)  changes  in  the 
temperature  of  the  air,  inducing  precipitation  of  the  con- 
tained moisture.  There  is  constant  evaporation  from  the 
surface  of  bodies  of  water  during  sunshine.     Considerable 


HYGROMETRY. 


39 


evaporation  also  takes  place  from  damp  soil.  The  degree 
of  humidity  of  the  air  at  a  particular  point  is  dependent 
principally  upon  the  rate  of  diffusion  through  which  the 

moist  air  is  replaced  by  drier 
air.  The  humidity  of  the  at- 
mosphere is  also  influenced 
through  precipitation.  When- 
ever the  air  of  a  locality  be- 
comes saturated  with  moisture 
and  then  is  cooled  suddenly, 
some  of  the  moisture  is  pre- 
cipitated in  the  form  of  rain, 
hail,  or  snow. 


^ 


n 


Fig.    3. — Psychrometer  :    <?,    dry-  FiG.  4. — The  hair  hygrometer :    a, 

bulb  thermometer;    b,  wet-bulb  ther-  b,    point    of    suspension    of    hair;     /, 

mometer;      c,     reservoir      containing  pointer;   <-,  a',  scale;  w,  weight, 
water. 

Hygrometry. — Hygrometr}^  is  the  determination  of 

the  amount  of  aqueous  vapor  in  the  air.  Hygrometers 
are  either  direct,  as  Daniell's  (Fig.  2),  Dine's,  and  Reg- 
nault's,  and  determine  directly  the  dew-point  of  the 
atmosphere  ;  or  indirect,  as  the  wet-  and  dry-bulb  ther- 


40  AIR. 

mometer,  or  psychrometer  (Fig.  3),  and  the  hair  hygrom- 
eter (Fig.  4). 

The  important  items  of  information  to  be  derived  from 
observations  with  hygrometers  are:  The  dew-point,  the 
vapor-tension  or  absolute  humidity,  and  the  relative  hu- 
midity of  the  atmosphere.  The  dew-point  is  that  tem- 
perature at  which  the  air  is  saturated  with  moisture,  so 
that  the  least  further  fall  in  temperature  causes  a  deposit 
of  moisture  in  the  form  of  dew.  The  higher  the  temper- 
ature of  the  air,  the  larger  the  amount  of  water  it  can 
contain  in  the  form  of  vapor ;  and  if  the  temperature  be 
lowered,  the  amount  of  moisture  remaining  the  same, 
eventually  a  point  will  be  reached  at  which  some  of  the 
moisture  is  precipitated.  This  temperature  is  indicated 
directly  by  the  condensation  hygrometers,  or  it  can  be 
calculated  from  the  readings  of  the  psychrometer,  with 
the  aid  of  tables  or  by  means  of  Apjohn's  formula  : 

E  =  elastic  force  of  vapor  corresponding  to  the  dew-point, 
e  =  elastic  force  corresponding  to  temperature  of  evaporation  (wet-bulb  ther- 
mometer), 
/=  dry-bulb  temperature, 
i^  =  wet-bulb  temperature,  and 
A  =■  height  of  barometer  in  millimeters. 

E=.e  —  0.01147  {l—t')  X  '■^^^■ 

h  —  €  1 

For  pressures  of  about  760  millimeters,  ■   may  be 

o 

neglected,  and  the  formula  becomes 

E=.e  —  iL—J}) 

87 

For  temperatures  below  0°  C.  the  formula  is 

^  _     i  —  /' 

~'  96    ■ 

The  tension  {E)  of  the  aqueous  vapor  in  the  atmos- 
phere may  be  calculated  from  the  readings  of  the  wet- 
and  dry-bulb  thermometers  by  means  of  the  following 
empirical  formula: 

E  =^e^  —  0.00077  (/  —  i'^)  X  ^h 


RELATIVE  HUMIDITY.  41 

in  which  e^  is  the  maximum  tension  corresponding  to 
the  temperature  of  the  wet-bulb  thermometer  (Ganot). 

If  the  dew-point  is  known,  either  by  calculation  from 
the  readings  of  the  wet-  and  dry-bulb  thermometers,  or 
by  direct  observation  by  means  of  the  hygrometer,  the 
elastic  force  or  tension  of  vapor  present  in  the  atmos- 
phere is  found  immediately  by  reference  to  a  table  of 
tensions. 

:^lastic  Force  of  Vapor. — This  is  the  amount  of 
barometric  pressure  due  to  the  vapor  present  in  the  air. 
The  tension  of  aqueous  vapor  at  100°  C.  temperature  is 
760  millimeters — that  is,  the  pressure  of  i  atmosphere. 
At  lower  temperatures  the  elastic  force  of  vapor  is  less 
than  at  100°  C.  It  is  greatest  within  the  tropics  and 
diminishes  toward  the  poles;  it  is  greatest  over  the 
ocean,  and  decreases  as  we  pass  inland;  it  is  greater  in 
summer  than  in  winter;  it  is  greater  at  midday  than  in 
the  morning;  and  it  generally  diminishes  with  increased 
elevation. 

Absolute  Humidity. — This  is  the  weight  of  water  in 
the  form  of  vapor  contained  in  a  given  volume  of  air  ex- 
pressed in  grams  per  cubic  meter.  It  varies  with  the 
temperature,  and  it  may  be  computed  from  the  readings 
of  the  wet-  and  dry-bulb  thermometers  by  the  use  of 
tables. 

Relative  Humidity. — Complete  saturation  of  the  air 
being  taken  as  100,  any  degree  of  dryness  may  be  ex- 
pressed in  percentage.  The  amount  of  aqueous  vapor 
actually  present,  and  the  amount  that  would  be  present 
if  the  air  were  saturated,  being  known,  the  former  is  ex- 
pressed as  a  percentage  of  the  latter,  giving  the  relative 
humidity.  Relative  humidity  is  greatest  near  the  surface 
of  the  earth  during  night,  when  the  temperature,  being 
at  or  near  the  daily  minimum,  reaches  the  dew-point  ;  it 
is  also  great  in  the  morning,  when  the  sun's  rays  have 
evaporated  the  dew,  and  the  vapor  is  as  yet  diffused  only 
a  little  way  upward;  and  it  is  least  during  the  greatest 
heat  of  the  day. 


42  AIR. 

The  Influence  of  Humidity  on  Health. — The  amount 
of  relative  humidit}-  of  the  atmosphere,  or  its  comple- 
ment the  deficiency  of  saturation,  is  of  the  greatest  im- 
portance. The  temperature  of  the  body  is  regulated  b}- 
the  loss  of  heat  by  evaporation  from  the  lungs  and  skin. 
At  a  temperature  of  15°  C. ,  and  with  the  relative  hu- 
midity at  75  per  cent,  Pettenkofer  and  Voit  estimated 
the  loss  of  water  from  the  lungs  at  286  grams,  and  from 
the  skin  at  500  to  1700  grams  daily.  If  the  relative 
humidity  be  increased,  there  will  be  a  hindrance  to  the 
escape  of  water  from  the  body;  and  when  this  condition 
is  combined  with  a  high  temperature  the  heat  is  far  more 
oppressive  than  when  the  atmosphere  is  dry  and  allows 
free  evaporation.  On  the  other  hand,  a  moist,  cold 
atmosphere  is  far  more  distressing  than  when  the  air  is 
dry  and  there  is  but  little  movement. 

Movements  of  the  Atmosphere. ^The  air  is  in  con- 
stant motion  as  the  result  of  changes  in  temperature 
affecting  the  density  of  the  air  of  certain  localities,  the 
less  dense  or  heated  air  being  displaced  by  the  colder, 
denser  air.  The  direction  in  which  the  movement  takes 
place  is  always  along  the  line  of  least  resistance  and 
toward  the  point  of  less  density.  The  rapidity  of  the 
movement  is  directly  proportional  to  the  magnitude  of 
the  change  in  density — that  is,  the  rise  in  temperature. 
The  most  important  cause  of  these  movements  is  the 
relatively  larger  amount  of  heat  transmitted  by  the  sun 
in  the  tropics,  which  gives  rise  to  what  are  known  as 
"trade"  winds.  The  varying  amounts  of  heat  trans- 
mitted by  the  sun  in  different  latitudes  and  at  different 
altitudes,  and  the  variations  in  the  temperature  due  to 
the  revolutions  of  the  earth  on  its  axis,  are  the  principal 
causes  of  winds.  These  movements  of  the  atmosphere 
play  an  important  part  in  the  regulation  of  temperature 
and  of  the  humidity  of  the  air.  If  they  did  not  occur, 
air  would  be  perpetually  warm  in  some  places  and  per- 
petually cold  in  others.  The  wind  carries  warm  air  to 
cold  regions  and  cold  air  to  warm  regions,  thus  tempering 
the  climate  of  each.     The  wind  also  prevents  the   air 


PRECIPITATION  OF  MOISTURE.  43 

from  remaining  excessively  dry  in  some  regions  and  in- 
ordinately damp  in  others. 

The  eflfects  of  wind  upon  health  are  complex  and 
not  well  defined.  All  wind,  or  movement  of  the  air, 
favors  evaporation,  and  therefore  loss  of  heat  from  the 
body,  unless  the  wind  itself  be  warm  and  moist;  a  hot, 
dry  wind  favors  evaporation  but  does  not  lower  the  tem- 
perature; a  cold,  moist  wind  lowers  the  temperature  but 
does  not  increase  the  evaporation.  Winds  that  are  warm 
and  moist  are  mild  and  relaxing ;  dry,  cool  winds  are 
bracing ;  but  cold  winds  are  penetrating,  and  are  con- 
sidered dangerous  to  persons  of  delicate  constitution. 

Clouds. — When  the  condensed  moisture  of  the  air 
collects  as  fog  in  the  lower  strata  and  rises  into  the  upper 
strata  it  takes  the  form  and  appearance  which  we  call 
clouds.  Clouds  moderate  radiation,  both  solar  and  ter- 
restrial, and,  therefore,  have  an  equalizing  influence  on 
the  temperature.  Their  amount  is  estimated  from  o 
(clear  sky)  to  10  (entirely  overcast).  There  is  most  cloud 
in  winter,  in  the  middle  of  the  day,  and  least  in  May 
and  June,  during  the  night. 

Precipitation  of  Moisture. — The  amount  of  cloud- 
formation  bears  a  certain  relation  to  the  amount  of  pre- 
cipitation. According  to  the  temperature  of  the  air,  the 
precipitation  takes  place  in  the  form  of  rain,  snow,  hail, 
or  sleet.  The  amount  of  rainfall  in  a  locality  is  depend- 
ent to  a  certain  extent  upon  its  vicinity  to  large  bodies 
of  water,  upon  the  direction  of  the  prevailing  winds, 
upon  the  altitude,  and  upon  the  latitude.  The  nature 
and  extent  of  the  soil-covering  of  the  locality  also  have 
a  direct  influence  upon  the  amount  of  rainfall,  as  shown 
by  the  diminished  rainfall  in  localities  where  the  forests 
have  been  destroyed.  The  immediate  eflect  of  a  fall  of 
rain  is  to  cleanse  and  purify  the  air  from  dust  of  all  sorts, 
orsfanic  and  inorganic,  and  from  micro-org:anisms.  Its 
action  with  regard  to  the  micro-organisms  is  twofold:  It 
not  only  washes  them  out  of  the  air,  but  it  tends  to  pre- 
vent their  rising  from  the  soil  by  rendering  the  surface 


44  AIR. 

of  the  ground  moist.  So  far  the  influence  of  rain  is  de- 
cidedly beneficial  to  health;  but  when  rainfall  is  so  ex- 
cessive as  largely  to  increase  the  humidity  of  the  air,  its 
hygienic  effect  becomes  merged  in  that  of  humidity. 
Also,  when  the  amount  is  so  great  as  to  render  the  soil 
waterlogged  its  effect  becomes  overshadowed  by  the 
effects  of  a  damp  soil. 

Climate. — By  climate  we  understand  all  the  meteoro- 
logic  conditions  of  a  place  or  locality  which  have  an 
influence  upon  health.  Along  with  these  conditions  the 
character  of  the  soil  is  also  an  important  factor  in  de- 
termining and  regulating  the  nature  of  the  climate  of  a 
locality.  Of  all  these  conditions,  meteorologic  and  tel- 
luric, temperature  is  the  most  important  in  determining 
the  character  of  a  climate,  while  humidity  is  the  factor 
next  in  importance.  Buchan  states  that  there  are  four 
principal  factors  in  the  production  of  the  climate  of  any 
locality:  (i)  Distance  from  the  equator;  (2)  height  above 
the  sea-level;  (3)  distance  from  the  sea;  and  (4)  prevailing 
winds.  Of  the  various  classifications  of  climates  that 
have  been  proposed,  perhaps  as  satisfactory  as  any  is  one 
that  rests  mainly  upon  the  first  three  conditions  named, 
the  fourth  condition,  that  of  the  prevailing  winds,  intro- 
ducing important  modifications.  Of  all  the  factors,  dis- 
tance from  the  equator  is  incomparably  the  most  potent, 
but  irregularities  in  the  distribution  of  land  and  water, 
and  the  prevalence  of  particular  winds,  often  bring  about 
a  subversion  of  what  Humboldt  calls  the  solar  climate 
of  the  earth.  Differences  of  elevation  also  cause  great 
differences  in  the  climate  of  nearly  adjacent  places. 

Climates  may  be  divided  into  tropical,  temperate, 
and  polar;  and  the  first  two  of  these  may  be  subdivided 
into  continental,  maritime,  and  mountain  climates.  A 
continental  climate  is  subject  to  the  extremes  of  heat 
and  cold;  has  an  atmospheric  pressure  that  is  normal;  a 
moderate  rainfall;  slight  humidity;  often  a  clear  sky; 
and  variable  winds.  A  maritime  climate  is  equable — 
that  is,  without  extremes  of  temperature;  with  consider- 


CLIMA  TE. 


45 


Normal  Temperature  and  Rainfall  in  the  United  States 

At  Weather  Bureau    Stations;    also  Highest   and  Lmuest   Temperatures   ever 

Reported  to  Septeviber  j,  i8gg. 


Stations. 

Temperature. 

nual 
tion. 
and 
low. 

States  and 

Mean. 

Extreme. 

a  a      5 

territories. 

Jan. 

July. 

High- 
est. 

Low- 
est. 

5  f>  c- 'oj 

g  a«  E 
2 

°C. 

°C. 

°C. 

°C. 

Cm. 

Alabama  .... 

1  Mobile  .... 

lO.O 

27.7 

38.3 

-18.3 

157.9 

1  Montgomery   . 

8.8 

27.7 

41.6 

—20.5 

133-7 

Arizona     .... 

Yuma 

12.2 

33-3 

47-7 

-5-5 

7.6 

Arkansas  .... 

f  Fort  Smith   .    . 
1  Little  Rock  .    . 

I.I 

26.t) 

42.2 

— 26.1 

II3-5 

4-4 

27-3 

40-5 

—22.2 

136,1 

(  Red  Bluff     .    . 

7-7 

27.7 

45-5 

-7-7 

66.2 

California.    .    .    . 

\  Sacramento  .    . 

7-7 

22.2 

43-3 

-8.3 

53-0 

(San  Diego    .    . 

12.2 

19.4 

38.3 

—0.0 

26.6 

Colorado  .... 

Denver 

—2.7 

22.2 

40-5 

-33-8 

36.3 

Connecticut.    .    . 

New  Haven .    .    . 

-2.7 

22.2 

37-7 

-25-5 

127.7 

Delaware  .... 

Del.  Breakwater. 

-0-5 

22.7 

33-8 

—17.2 

82.8 

Dist.  of  Columbia 

Washington      .    . 

-0.5 

25.0 

40.0 

—26.1 

1 10.4 

Florida      .... 

f  Jacksonville      . 

12.7 

27.7 

40.0 

— 12.1 

137-3 

(  Key  West     .    . 

21. 1 

28.8 

37-7 

5-0 

97-7 

(Atlanta.    .    .    . 

6.1 

25-5 

37-7 

—22.2 

132.0 

Georgia     .... 

]  Savannah .    .    . 

lo.i 

2.7.7 

40-S 

-13-3 

131-8 

Idaho    

Boise 

—2.2 

23-3 

41.6 

-33-3 

33-5 

Illinois 

(  Chicago     .    .    . 

-3-3 

22.2 

37-7 

-30.S 

88.3 

\  Springfield   .    . 

-3-8 

25.0 

38.8 

—30.0 

96.5 

Indiana     .... 

Indianapolis     .    . 

—2.2 

24.4 

38.3 

-31-7 

109.2 

Indian  Territoiy 

Fort  Sill     .... 

.    ^-3 

27.7 

41.6 

—22.7 

79-2 

Iowa 

1  Des  Moines  .    . 

-8.3 

23-7 

40.0 

-34-4 

84.0 

j  Keokuk     .    .    . 

-50 

25.0 

40.0 

-3I-I 

90-4 

Kansas      .... 

Dodge 

-3-8 

25-5 

42.2 

—32.2 

50.2 

Kentucky.    .    .    . 

Louisville .... 

I.I 

26.1 

40-5 

-28.8 

116.3 

Louisiana.    .    .    . 

j  New  Orleans   . 
(  Shreveport    .    . 

12.2 
7-3 

28.3 
28.3 

37-3 
41.6 

-13-9 
-20.5. 

153-6 
123.4 

Maine 

j  Eastport    .    .    . 

-5-0 

iS-5  • 

32-7 

—29.4 

114.8 

1  Portland   .    .    . 

-6.6 

20.7 

36.1 

-27-3 

107.4 

Maryland      .    .    . 

Baltimore      .    .    . 

I.I 

25-5 

40.0 

21.6 

III. 2 

Massachusetts .    . 

Boston 

-3-3 

21.6 

38.3 

-25.0 

1 14-3 

Michigan .... 

1  Marquette    .    . 
(  Port  Huron  .    . 

—8.8 
-6.1 

18.3 
20.7 

37-7 
37-3 

-32.7 
-31-7 

82.2 
80.2 

Minnesota    .    .    . 

f  Duluth  .... 
1  St.  Paul     .    .    . 

—12.2 

18.8 

37-3 

-41.7 

78.7 

-1 1. 7 

22.2 

37-7 

-41.7 

69.8 

Mississippi    .    .    . 

Vicksburg     .    .    . 

8.3 

27.7 

38.3 

-18.3 

141-4 

Missouri  .... 

f  St.  Louis  .    .    . 

—I.I 

26.1 

41. 1 

-30.5 

104.3 

1  Springfield    .    . 

0.0 

23-7 

38.8 

-33-8 

116. 0 

Montana  .... 

Havre    ..... 

-12.7 

19.4 

42.2 

-48.3 

35.8 

I^ebraska 

J  Omaha  .... 

-7-3 

24.4 

41. 1 

-3So 

80.5 

i  Valendne  ... 

— lO.O 

23-3 

41.1 

-38.8 

48-5 

Nevada 

Winnemucca   .    . 

—2.2 

22.2 

40.0 

-33-3 

21.5 

North  Carolina    . 

/  Hatteras    .    .    . 

6.6 

25-5 

33-3 

-13-3 

168.6 

j  Wilmington  .    . 

8.3 

26.6 

39-4 

-15.0 

137-8 

North  Dakota 

/  Bismark     .    .    . 
1  Williston  . 

-iS-5 

19.4 

40-5 

—42.2 

46.7 

—16. 1 

20.0 

41.6 

-450 

35-5 

New  Hampshire 

Manchester  .    .    . 

-S-5 

20.7 

3S-S 

-239 

106.4 

New  Jersey  ,    .    . 

J  Cape  May     .    . 

I.I 

23-3 

327 

-n.4 

119.8 

1  New  Brunswick 

—2.2 

233 

37-7 

-233 

118.8 

New  Mexico    .    . 

Sante  Fe  .    .    .    . 

— 2.2 

20.0 

36.1 

-25.0 

40-S 

("Albany      .    .    . 

-5.0 

22.7 

37-7 

-27.7 

96.2 

New  York     .    .    . 

-j  New  York     .    . 

—  I.T 

233 

37-7 

—21. 1 

II3-7 

( Oswego     .    .    . 

-3-8 

20.7 

37-7 

-30-5 

88.9 

46 


AIR. 


States  and 
territories. 


Ohio 


Oresjon  , 


Pennsylvania 

Rhode  Island 
South  Carolina 
South  Dakota 

Tennessee    . 


Texas    .    .    . 

Utah  .... 
Vermont  .    . 

Virginia    .    . 

Washington . 
West  Virginia 
Wisconsin     . 
Wyoming     . 


Stations. 


f  Cincinnati 
I  Toledo  . 
f  Portland 
I  Roseburg 
I  Philadelph 
I  Pittsburg 

Newport    . 

Charleston 

Yankton    . 
I  Memphis 
I  Nashville 
]y\  Paso 
[  Palestine 

Salt  Lake  . 

Burlington 
\  Lynchbur 
{Norfolk.  ' 
I  Dayton  . 
I  Olympia 

Morgan  town 
J  La  Crosse 
(  Milwaukee 

Cheyenne 


Temperature. 

Mean. 

Extreme. 

Jan. 

July. 

High- 
est. 

Low- 
est. 

°C. 

°C. 

°C. 

°C. 

-0.5 

25 -S 

40.0 

-27-3 

-3-3 

22.7 

37-3 

-26.6 

3-8 

19.4 

38.8 

-18.8 

4.4 

18.8 

40.0 

—21. 1 

0.0 

24.4 

38.8 

—21. 1 

—I.I 

22.7 

39-4 

-28.8 

—I.I 

21. 1 

33-3 

—22.2 

9.4 

27.7 

40.0 

-13.9 

-lo.S 

22.7 

39-4 

-36.6 

4.4 

27-3 

38.8 

—22.7 

3-3 

26.6 

40.0 

—25.0 

6.6 

27.7 

45 -o 

—20.5 

6.1 

27.7 

40.0 

-21. 1 

—2.2 

24.4 

38.8 

-28.8 

-7.2 

21.6 

36.1 

-31-7 

2.2 

25-5 

38.8 

—21. 1 

4-4 

26.1 

38.8 

-16.6 

—I.I 

20.0 

42.7 

— 32.2 

3-3 

16.6 

36.1 

-18.8 

1.6 

■23.3 

3b.i 

-31-7 

-9.4 

22.7 

38.3 

-41.6 

—7.2 

20.7 

37-7 

-31-7 

-3-8 

19.4 

37-7 

-38.8 

rt  c  y  ^ 


iIaI 


Cm. 
IOI.3 

78.4 
118.8 

89.4 
101.2 

93-2 
127.0 

143-9 
68.0 

I3S-3 
127.2 

23.6 
118. 1 

41. 1 

72.2 
108.6 
132.3 

70.5 
134.8 
119. 1 

77-9 
81,5 

30-9 


Note. — The  minus  (  — )  indicates  temperature  below  o  °  C. 

able  atmospheric  pressure;  considerable  humidity;  moder- 
ate rainfall;  a  misty  or  cloudy  sky;  winds  often  regular. 
A  mountain  climate  has  a  lower  temperature  and  less 
pressure  than  the  preceding;  considerable  rainfall;  large 
relative,  but  small  absolute,  humidity;  sky  often  clear, 
consequently  considerable  terrestrial  radiation  and  low 
night  temperature;  and  winds  determined  by  the  con- 
figuration of  the  earth's  surface. 

Some  idea  as  to  the  climatic  conditions  of  different 
localities  in  the  United  States  may  be  gained  by  refer- 
ence to  the  following  table,  showing  the  mean  and  ex- 
treme temperature,  and  the  mean  precipitation  of  these 
localities: 

The  Influence  of  Climate  on  Health. — In  warm 
climates  the  functions  of  the  liver  and  skin  are  particu- 
larly active;  the  digestion  is  not  vigorous,  though  the 
activity  of  intestinal  peristalsis  is  often  great;  the  ner- 
vous system  is  excited  or  depressed   according   to   the 


INFLUENCE  OF  CLIMATES  UPON  THE  BODY.     47 

degree  of  humidity  of  the  air.  In  cold  climates  the 
digestive  functions  are  vigorous;  the  nervous  system 
sluggish;  muscular  development  large;  and  life  generally 
prolonged  in  spite  of  the  severity  of  the  climate.  In 
temperate  climates,  which  on  the  whole  are  the  healthiest, 
there  is  no  great  strain  on  the  liver,  digestive  organs,  and 
skin  as  in  hot,  nor  on  the  lungs  and  kidneys  as  in  cold 
and  damp  climates. 

A  climate  of  a  place  where  the  air  has  a  relative  humid- 
ity of  less  than  25  per  cent,  is  unusually  dry,  as,  for 
instance,  in  desert  regions  where  the  rainfall  is  very  low. 
A  relative  humidity  of  25  to  40  per  cent,  is  generally 
regarded  as  dry  air.  A  relative  humidity  of  40  to  60 
per  cent,  is  most  agreeable  and  gives  rise  to  no  dis- 
comfort. A  relative  humidity  of  60  to  80  gives  a  sensa- 
tion of  moist  air,  while  still  higher  percentages  of  moist- 
ure are  encountered  in  moist  atmospheres.  The  char- 
acter of  a  climate  is,  however,  also  influenced  by  the 
temperature  as  well  as  the  relative  humidity.  At  low 
temperatures,  but  more  especially  at  high  temperatures, 
the  relative  humidity  of  the  atmosphere  plays  a  most 
important  role  in  determining  the  healthfulness  of  the 
climate  of  a  locality. 

Influence  of  Tropical  Climates  upon  the  Body. — 
Kohlbriigge  ^  sought  to  determine  the  influence  of  tropi- 
cal climates  upon  the  body  by  means  of  two  tests  :  the 
bleaching  of  the  skin  and  the  elasticity  of  the  tissues. 
The  bleaching  of  the  skin  of  Europeans  in  the  tropics  is 
not  always  an  evidence  of  permanent  tropical  anemia,  as 
he  has  found  it  to  exist  in  many  persons  in  whom  the 
blood  count  and  hemoglobin  were  normal.  In  these 
instances  he  believes  the  bleaching  is  brought  about 
through  the  influence  of  the  free  perspiration  due  to  the 
high  temperature  and  in  consequence  of  the  saturation 
of  the  superficial  layers  of  the  skin  because  of  the  hyper- 
emia of  certain  vascular  systems  of  the  skin,  as  a  result 
of  which  there  is  a  thickening  of  these  layers,  so  that 
the  coloring-matter  of  the  blood  can  no  longer   be  seen 

^  Arch.  f.  Schij^s-u.  Tropenhyg.,  1900,  p.  20. 


48  AIR. 

througli  it.  Since  evaporation  from  the  skin  is  inhibited 
because  of  the  high  atmospheric  humidity,  this  bleach- 
ing effect  remains  permanent  during  residence  in  the 
tropics.  Upon  changing  to  a  temperate  climate  the 
horny  layer  of  the  skin  again  becomes  thinner  in  conse- 
quence of  diminished  nutrition  and  more  ready  evapora- 
tion, and  the  coloring-matter  of  the  blood  again  becomes 
visible. 

The  tropical  climate  acts  upon  the  elasticity  of  the 
tissues  most  probably  in  such  a  manner  that  the  elasticity 
of  the  different  tissue-fibers  is  increased  through  the 
action  of  the  heat.  This  is  shown  not  only  in  natives, 
but  also  in  the"  descendants  of  Europeans  born  in  the 
tropics,  and  manifests  itself  in  greater  joint  movement 
and  in  oreneral  slug^orishness  and  relaxation. 

Influence  of  Tropical  Climate  on  Nutrition. — 
K.  E.  Ranke  ^  made  a  study  of  the  influence  of  climate 
on  nutrition  during  a  journey  to  South  America. 

The  optimum  temperature  of  the  European  with 
medium  clothing  is  15°  to  18°  C,  if  none  of  the  other 
climatic  factors  produces  any  definite  action.  In  a  climate 
with  a  temperature  of  18°  to  22°  C.  there  is  increased 
evaporation  of  water,  but  no  definite  influence  upon  the 
appetite.  In  a  climate  of  about  25°  C,  when  the  other 
climatic  factors  neither  increase  nor  decrease  the  action 
of  the  temperature,  there  is  a  marked  diminution  in  the 
appetite.  With  further  increase  in  the  temperature  there 
is  also  further  decrease  in  appetite,  and  at  last  it  sinks 
below  the  requirements  of  an  adult  at  complete  rest. 
The  protein  nutrition  does  not  sink  below  the  mainte- 
nance minimum  of  the  lower  laboring-classes  ;  each  fur- 
ther diminution  being  made  at  the  expense  of  the  fats 
and  carbohydrates.  If  there  is  opposition  to  this  instinc- 
tive diminution  of  the  appetite,  pathologic  effects  mani- 
fest themselves  :  disturbance  of  the  general  comfort, 
increased  temperature,  and  decrease  of  the  natural  resist- 
ance against  infectious  diseases.  If  the  nutrition  is  con- 
stantly diminished  below  that  required  because  of  the  heat 
^August  Hirschwald,  Berlin,  1900. 


INFLUENCE  OF  CLIMATE  ON  NUTRITION.      49 

elimination  in  a  very  hot  climate,  the  deficient  nutrition 
leads  to  dangerous  consequences. 

F.  Hueppe^  states  that  the  dangers  encountered  by 
Europeans  in  the  tropics  in  regions  of  less  than  2000 
meters'  elevation  are  constant  high  temperature  com- 
bined with  high  atmospheric  humidity.  These  factors 
call  forth  increased  efforts  to  cool  the  body,  and  hence 
affect  the  activity  of  the  skin,  heart,  and  lungs.  The 
results  of  this  increased  activity  are  noticed  in  fatigue  on 
slight  exertion  and  decreased  nervous  and  muscular 
power. 

The  high  sensibility  of  the  digestive  organs  of  the 
European  in  the  tropics  is  caused  by  the  dilution  of  the 
digestive  fluids  from  increased  ingestion  of  fluids  induced 
by  the  free  perspiration.  All  these  conditions  vary  in 
different  individuals.  General  exercise,  especially  in  the 
form  of  riding  and  swimming,  is  beneficial  for  all  the 
body  functions.  The  tropical  climate  operates  especially 
unfavorably  upon  the  female  organism. 

The  greatest  enemy  of  the  European  in  the  tropics  is 
alcohol,  the  misuse  of  which  increases  enormously  all 
the  other  unfavorable  and  detrimental  influences.  The 
infectious  diseases,  as  yellow  fever,  cholera,  plague,  dys- 
entery, and  malaria,  are  the  next  greatest  detrimental 
influences  in  the  tropics. 

The  influence  of  climate  upon  the  course  of  certain 
diseases  has  been  the  subject  of  numerous  observations. 
The  influence  of  a  dry  climate  upon  the  course  of  tuber- 
culosis is  now  well  understood.  The  rarefied  air  as  found 
in  the  Rocky  Mountain  region  seems  to  be  of  great  value 
in  the  treatment  of  this  disease.  This  condition  of  the 
atmosphere  produces  an  augmented  respiratory  activity 
which  is  highly  beneficial  in  early  stages  of  consump- 
tion. 

The  value  of  pine  forests  in  localities  having  a  dry, 
sandy  soil  and  a  climate  of  low  relative  humidity  is  also 
generally  recognized.      The  pine  belts  of  New  York, 

^Berlin,  klin.  Wochenschr.,  1901,  p.  7. 


50  AIR. 

New  Jersey,  and  North  Carolina  are  especially  adapted 
for  consumptives  during  the  winter  months  of  the  year. 

Probably  the  chief  value  of  removal  to  another  climate 
in  the  early  stages  of  consumption  is  to  be  traced  to  the 
changed  conditions  of  life.  The  outdoor  life  which  these 
localities  usually  permit,  along  with  the  high  percentage 
of  clear,  days,  and  the  removal  from  the  anxieties  and 
constraints  of  business  life,  are  as  beneficial  as  the  climate 
itself,  if  not  more  so.  The  conviction  that  this  is  the 
case  has  led  a  number  of  prominent  physicians  to  advo- 
cate the  high  plateaus  of  the  Blue  Mountains  in  eastern 
Pennsylvania  as  a  desirable  locality  for  the  recuperation 
of  those  likely  to  be  benefited  by  change  of  climate.  The 
locations  which  have  been  specially  advocated  are  Pocono 
Mountain  in  Monroe  County  and  Green  Mountain  in 
Lehigh  County.  This  region  is  the  natural  home  of  the 
pine,  though  the  operations  of  the  lumbermen  have  long 
since  caused  its  almost  total  disappearance.  The  State 
of  Pennsylvania  is  acquiring  a  number  of  large  areas  of 
land  in  different  parts  of  the  State  for  forest  reservations, 
and  in  time  these  will  be  valuable  localities  for  the  estab- 
lishment of  institutions  for  the  climatic  treatment  of  dis- 
eases similar  to  those  found  in  the  Adirondack  region  of 
New  York  and  elsewhere. 

vSanitoria  for  the  treatment  of  incipient  and  advanced 
cases  of  tuberculosis  are  now  maintained  by  the  vState 
of  Pennsylvania  at  Mont  Alto  in  Franklin  County,  at 
Cresson  in  Cambria  County,  and  at  Hamburg,  Berks 
County. 

Influence  of  Climate  and  Season  on  Mortality. — 
The  seasonal  variations  alone  in  the  temperate  zone  are 
of  great  influence  upon  mortality  aside  from  the  general 
climatic  conditions  of  a  locality.  Mild  winters  and  cool 
summers  both  lower  the  mortality,  the  former  exerting  a 
special  influence  upon  the  aged,  and  the  latter  upon  the 
young,  more  particularly  the  infantile  population.  A 
cool,  damp  summer  is  always  accompanied  by  a  low  mor- 
tality. Season  has  also  an  important  influence  upon  the 
character  of  the  prevalent    diseases — intestinal    diseases 


INFLUENCE  OF  CLIMATE  ON  MORTALITY.      51 

being  most  prevalent  in  summer  and  respiratory  diseases 
in  winter.  Typhoid  fever  is  least  prevalent  in  late  spring 
and  early  summer,  and  most  prevalent  in  the  autumn. 
Typhoid  fever  reaches  its  mean  about  the  end  of  the 
year;  then  there  occurs  a  gradual  fall  to  a  minimum  in 
April,  sometimes  interrupted  by  a  slight  outbreak  in 
January  or  February.  There  is  also  a  June  or  July  mini- 
mum with  a  more  rapid  rise  to  maximum  about  the  end 
of  October  or  beginning  of  November.  The  curve  of 
scarlet  fever  is  very  similar  to  that  of  typhoid  fever,  but 
its  minimum  is  in  March,  and  it  rises  gradually  to  a 
maximum  early  in  November. 

Acclimatization  is  that  process  by  which  animals  or 
plants  become  adapted  to,  and  so  thrive  in,  a  climate 
different  from  that  in  which  they  are  indigenous.  For 
instance,  almost  all  the  domestic  animals  were  originally 
natives  of  warm  climates.  As  regards  man,  Arnould 
states  that  the  race  is  acclimatized  when  it  preserves  (i) 
the  natural  increase  in  population;  (2)  its  normal  lon- 
gevity; (3)  its  aptitude  for  physical  and  intellectual  work. 
He  gives  the  following  as  conditions  favorable  to  the 
acclimatizing  process:  i.  Slight  alteration  in  the  lati- 
tude: to  proceed  from  a  w^armer  to  a  colder  climate  is  an 
advantage.  2.  Ethnical  disposition.  3.  Manners  and 
customs.  It  is  essential  to  adapt  one's  diet  to  the  climate. 
Clothing  and  general  habits  should  also  be  assimilated  to 
the  altered  conditions  of  climate.  4.  Aptitude  for  cross- 
breeding. 5.  Soil  and  locality:  where  the  soil  is  not  un- 
healthy, acclimatization  is  much  simplified;  if  an  un- 
healthy soil  is  made  healthy,  by  drainage,  etc. 

It  is  evident  that  a  large  part  of  the  influences  attributed 
to  changes  in  climate  is  in  reality  due  to  the  prevalence 
of  certain  diseases  in  different  localities  which  are  absent 
in  others.  For  instance,  those  passing  from  the  temper- 
ate zone  into  the  tropical  zone  encounter  diseases  which 
are  unknown  in  the  temperate  region,  and  for  which  they 
possess  neither  a  congenital  nor  acquired  immunity  and 
hence  are  highly  susceptible  to  such  infections.  After 
they  have  acquired  an  immunity  against  such  diseases,  it 


52  AIR. 

is  probable  that  the  more  important  feature  of  their 
acclimatization  has  been  accomplished. 

Ground-air. — The  atmosphere  does  not  stop  at  the 
surface  of  the  soil,  but  penetrates  into  all  the  pores  and 
crevices.  The  proportion  of  air  in  the  soil  is  not  great 
where  there  are  no  fissures  or  clefts,  but  in  the  superficial 
layer  air  is  always  present  in  appreciable  proportions, 
and  especially  so  in  made  soil.  Soil-air  is  of  somewhat 
different  composition  than  the  atmospheric  air.  We  find 
present  in  it  large  quantities  of  the  products  of  putrefac- 
tion, which  is  very  active  in  the  soil.  It  is,  therefore, 
far  richer  in  carbon  dioxid,  besides  containing  other 
hydrocarbons  as  the  result  of  putrefaction,  principal 
among  which  is  marsh  gas.  In  subterranean  caverns  the 
air  may  have  undergone  such  an  amount  of  change  as 
the  result  of  putrefaction  and  chemical  changes  going  on 
in  the  rocks  that  it  is  not  fit  for  respiration,  and  may  be 
highly  inflammable  as  the  result  of  the  admixture  of 
other  gases.  Soil-air  is  therefore  injurious  if  inhaled  in 
large  quantities  and  for  a  long  time.  It  tends  to  pene- 
trate into  houses  from  the  surrounding  soil,  because  the 
warmer  air  of  the  house  has  an  upward  tendency  and 
thus  abstracts  the  air  from  the  soil.  For  this  reason 
newly  made  soil  is  considered  unhealthy  and  should  be 
avoided.  This  is  especially  the  case  with  the  newly 
made  soil  in  and  around  cities,  where  the  materials  em- 
ployed in  making  the  soil  are  frequently  such  as  are 
capable  of  undergoing  putrefaction. 

Sewer-air. — Sewer-air  in  properly  constructed  modern 
sewers  is  merely  atmospheric  air  which  contains  a  slight 
excess  of  carbon  dioxid  and  small  amounts  of  gases 
resulting  from  putrefaction  taking  place  in  the  sewage. 
Consequently  there  is  also  a  slight  decrease  in  the  pro- 
portion of  oxygen  present.  The  proportion  of  micro- 
organisms is  usually  less  than  that  of  the  air  of  streets 
and  houses,  and  they  are  usually  harmless  species.  The 
movement  of  air  in  sewers  is  rather  slow,  and  affords 
abundant  opportunity  for  the  suspended  particles,  along 
with  the  micro-organisms,   to  become  deposited  on  the 


THE  IMPURITIES  IN  AIR.  53 

moist  walls  of  the  sewer.  When  a  portion  of  a  sewer  cr 
the  drainage-pipes  of  a  house  become  obstructed,  so  that 
there  is  no  longer  a  free  circulation  of  air  in  the  ob- 
structed portion,  then  there  is  an  accumulation  of  the 
gases  resulting  from  putrefaction,  such  as  carbon  dioxid, 
hydrogen  sulphid,  marsh  gas,  etc.,  and  these  gases  are 
highly  injurious  when  inhaled  in  considerable  quantities 
or  in  smaller  amounts  for  a  considerable  time. 

The  Impurities  in  Air. — These  are  either  gaseous  or 
solid.  The  more  important  gaseous  impurities  in  air  are 
carbon  monoxid  and  dioxid,  marsh  gas,  hydrogen  sul- 
phid, gaseous  organic  substances — such  as  amins,  ammo- 
nia, and  volatile  fatty  acids.  The  solid  impurities  in  air 
are  various  forms  of  dust,  inorganic  and  organic;  the 
debris  of  vegetable  and  animal  organisms,  and  living 
micro-organisms. 

Sources  of  the  Impurities. — Impurities  due  to  Respira- 
tion.— The  changes  that  take  place  in  air  that  has  been 
respired  are  both  chemical  and  physical,  (i)  The  volume 
of  the  expired  air  is  from  one-fiftieth  to  one-fortieth  less 
than  that  taken  in  at  the  corresponding  inspiration.  (2) 
The  temperatm-e  is  raised,  as  a  rule,  to  about  36°  C. 
(3)  Owing  to  this  rise  in  the  temperature  there  is  actually 
an  increase  in  volume  of  the  expired  over  the  inspired 
air  to  an  extent  of  about  one-ninth  of  the  latter.  (4)  There 
is  an  increase  in  the  amount  of  carbon  dioxid  to  between 
4  and  5  per  cent.  (5  and  6)  There  is  an  increase  of 
ammonia  and  watery  vapor.  (7)  The  nitrogen  is  generally 
increased,  but  sometimes  diminished.  (8)  The  oxygen  is 
diminished  to  about  16  per  cent.  There  is  an  addition 
to  the  air  of  (9)  hydrogen,  (10)  marsh  gas,  and  (11)  or- 
ganic matter.  Of  these  alterations,  the  most  important 
are  the  increase  in  the  amount  of  carbon  dioxid  and  the 
corresponding  decrease  in  the  amount  of  oxygen,  the 
increase  of  the  aqueous  vapor,  and  the  addition  of 
organic  matter. 

Carbon  Dioxid. — The  amount  of  carbon  dioxid  ex- 
creted has  been  variously  estimated  at  from  31.5  to  37.5 
grams  per  hour.   According  to  Pettenkofer  and  Voit,  the 


54  AIR. 

total  amount  excreted  in  twenty-four  hours  for  male 
adults  is,  on  an  average,  800  grams,  or  406  liters;  and 
according  to  Vierordt,  900  grams,  or  455.5  liters.  Assum- 
ing the  tidal  air  of  each  respiration  to  measure  500  cubic 
centimeters,  and  to  contain  4  per  cent,  of  carbon  dioxid, 
and  that  17  respirations  are  taken  every  minute,  then 
the  carbon  dioxid  excreted  in  one  hour  is  500  X  0.04 
X  17  X  60  =  20.4  liters,  or  489.6  liters  in  twenty-four 
hours. 

Aqueous  Vapor. — The  expired  air  contains  consider- 
able quantities  of  aqueous  vapor.  The  absolute  amount 
varies  with  the  ^temperature  of  the  expired  air;  but  this 
itself  varies  very  slightly,  being  nearly  that  of  the  blood, 
ranging  from  33.8°  to  36.1°  C.  According  to  Vierordt,  330 
grams  of  water  are  given  off  from  the  lungs  in  twenty- 
four  hours;  and  according  to  Valentine,  640  grams. 
Pettenkofer  and  Voit  state  that,  with  the  temperature  of 
the  atmosphere  at  15°  C.  and  the  relative  humiditv  at  75 
per  cent.,  an  adult  gives  off  286  grams  of  water  from  the 
lungs  in  twenty-four  hours. 

Organic  Matter. — That  organic  matter  is  present  in 
the  expired  air  is  obvious  from  its  odor,  which  is  often 
quite  fetid,  and  from  the  fact  that  when  it  is  collected  by 
the  condensation  of  the  aqueous  vapor  it  is  putrescible. 
It  has  been  supposed  by  some  that  this  organic  matter  is 
derived  from  the  alimentary  canal  and  from  the  upper 
portion  of  the  respiratory  tract,  but  it  has  apparently 
been  found  in  air  drawn  directly  from  the  trachea.  The 
greater  portion  of  it,  however,  arises  from  decomposing 
particles  of  food  lodged  between  the  teeth,  and  only 
a  small  portion  of  it  comes  directly  from  the  lungs. 
A  small  portion  of  it  is  also  derived  from  the  mucous 
membrane  of  the  pharynx  and  larynx  and,  probably, 
from  the  stomach. 

The  nature  of  the  organic  matter  is  not  known  with 
certainty.  It  decolorizes  solutions  of  potassium  perman- 
ganate, and  is,  therefore,  capable  of  being  oxidized. 
When  distilled  it  is  broken  up  and  yields  ammonia,  and 
is,  therefore,   nitrogenous.     It  is  molecular  rather  than 


THE  IMPURITIES  IN  AIR.  55 

gaseous,  and  is  probably  in  combination  with  water,  be- 
cause those  substances  which  are  most  hygroscopic  ab- 
sorb most  organic  matter.  The  quantity  of  organic 
matter  given  off  with  tlie  expired  air  lias  been  estimated. 
Cornelly,  Haldane,  and  Anderson  found,  in  ten  observa- 
tions, that  the  amount  of  oxygen  required  to  oxidize  the 
organic  matter  varied  from  1.7  to  13.6  milligrams  per 
liter  of  condensed  vapor,  giving  an  average  of  7.6  and 
8.3  milligrams  for  two  observers,  respectively.  Lehmann 
and  Jessen  found  that  between  3  and  4  milligrams  of 
oxygen  were  required  to  oxidize  the  organic  matter  in  a 
liter  of  condensed  vapor.  Ransome's  results  indicate  the 
exhalation  of  20  milligrams  of  organic  matter  in  twenty- 
four  hours,  and  Ben's  results,  15  milligrams.  In  my 
own  experiments  ^  I  found  the  quantity  of  organic  matter 
in  the  expired  air  of  health}^  men  to  be,  on  an  average, 
IQ.  72  milligrams  per  liter  of  condensed  vapor.  I  found 
also  that  the  amount  of  organic  matter  is  much  greater 
three  to  four  hours  after  a  meal  than  immediately  after 
eating,  and,  likewise,  that  the  amount  is  directly  de- 
pendent upon  the  degree  of  cleanliness  of  the  mouth  and 
teeth  of  the  person  from  whom  the  vapor  is  collected; 
the  average  amount  four  hours  after  meals  was  11.98 
milligrams,  half  an  hour  after  meals  it  was  only  3.86 
milligrams  when  the  mouth  and  teeth  had  remained  un- 
cleaned  for  several  days,  while  the  average,  four  hours 
after  meals,  was  only  2.49  milligrams  when  the  teeth  had 
first  been  brushed  and  the  mouth  thoroughly  rinsed  with 
warm  water.  The  amount  of  organic  matter  is  also 
greater  in  those  having  deca^'ed  teeth  than  in  those 
having  sound  teeth.  In  vapor  condensed  from  the  breath 
of  a  man  having  an  opening  directly  into  the  trachea, 
and  in  whom  there  was  no  communication  between  the 
trachea  and  pharynx,  I  found  the  average  for  three  ob- 
servations to  be  9.68  milligrams.  In  a  consumptive 
person  I  found  the  average  amount  to  be  17.34  milli- 
grams. I  found  the  average  amount  of  nitrogenous  or- 
ganic matter  given  off  with  the  expired  air  to  be  17.5 
^  Smithsonian  Contributions  to  Knowledge,  989,  Washington,  D.  C,  1895. 


56  AIR. 

milligrams  of  free,  and  9.0  milligrams  of  albuminoid, 
ammonia  per  liter  of  condensed  vapor,  for  healthy  persons; 
and  0.3  milligram  of  free,  and  3.4  milligrams  of  albu- 
minoid, ammonia  in  that  of  consumptive  persons. 

Bacteria  in  Expired  Air. — No  bacteria  are  given  off 
with  the  expired  air  in  ordinary,  quiet  respiration.  In 
the  forcible  expirations  during  speaking,  coughing,  or 
sneezing  it  has  been  found  that  small  particles  of 
mucus  and  moisture  are  thrown  off  which  carry  micro- 
organisms. In  this  manner  a  person  suffering  from  the 
various  infectious  diseases  may  infect  the  atmosphere  and 
the  furniture  of  the  room  in  which  he  lives.  It  must  be 
remembered,  however,  that  only  in  several  diseases  which 
are  localized  in  the  respiratory  tract  would  there  be  dan- 
ger of  the  dissemination  of  the  specific  disease-producing 
bacteria.  This  mode  of  dissemination  may  take  place  in 
tuberculosis  of  the  respiratory  tract,  in  diphtheria,  and  in 
pneumonia.  In  those  diseases  in  which  the  specific  bac- 
teria are  localized  in  some  other  part  of  the  body  there 
would  be  no  danger  of  their  dissemination  through  cough- 
ing, speaking,  etc. 

Persons  who  have  recently  recovered  from  diphtheria 
or  from  some  other  disease  of  the  upper  respiratory  tract, 
or  persons  who  have  been  in  close  contact  with  patients 
suffering  from  infection  of  the  upper  respiratory  tract 
may  carry  the  infecting  bacteria  in  their  throat  for  some 
time.  These  so-called  "carriers"  are  likely  to  contami- 
nate the  air  or  infect  the  furniture  in  a  room  in  the  same 
way  as  do  those  actually  suffering  from  disease. 

Impurities  due  to  Perspiration. — The  secretions  of  the 
skin  consist  of  sweat  proper  (an  acid,  watery  fluid  con- 
taining about  1.8  per  cent,  of  solids)  and  of  sebaceous 
matter,  and  the  quantity  varies  greatly  according  to  the 
temperature  and  humidity  of  the  air,  the  amount  of  ex- 
ertion, etc.,  but  may  be  taken  as  ranging  from  800  to 
1000  cubic  centimeters  during  twenty-four  hours.  Epi- 
thelial cells  are  constantly  disengaged  from  the  skin. 
Considerable  amounts  of  carbon  dioxid  are  also  given 
off  through  the  skin. 


THE  IMPURITIES  IN  AIR.  57 

Impurities  due  to  Combustion. — The  principal  impuri- 
ties due  to  combustion  are  carbon,  carbon  monoxid,  car- 
bon dioxid,  sulpliur,  sulphur  dioxid,  sulphuric  acid, 
sometimes  hydrogen  sulphid,  ammonia  compounds,  and 
water. 

'  The  impurities  arising  from  illuminating-gas  are  ole- 
fiant  gas  and  other  hydrocarbon  vapors,  hydrogen,  carbon 
monoxid,  and  marsh  gas.  Besides  these  normal  constitu- 
ents of  the  gas  we  frequently  find  present  carbon  dioxid, 
hydrogen  sulphid,  and  other  sulphur  compounds. 

Impurities  in  the  Air  of  Work-rooms  and  Factories. — 
The  air  of  work-rooms  and  factories  contains  the  im- 
purities arising  from  the  respiration  and  perspiration 
of  the  occupants,  and,  in  many  instances,  also  the  pro- 
ducts of  combustion  arising  from  the  process  of  heating 
and  lighting.  Such  rooms  are  often  overcrowded  and 
overheated,  and  in  consequence  these  impurities  are 
present  in  excessive  amounts,  while  from  lack  of  per- 
sonal cleanliness  there  is  a  greater  proportion  of  the 
organic  impurities  arising  from  perspiration. 

The  special  impurities  of  the  air  resulting  from  the 
manufacturing  processes  present  one  or  the  other  of  the 
following  conditions:  {a)  Increase  of  temperature,  as  in 
mines  or  bake-houses,  the  "  gassingr "  rooms  of  silk 
mills,  and  the  "sizing"  sheds  of  cotton  mills.  {6)  Ex- 
cessive humidity,  as  in  some  deep  mines  and  in  the 
"sizing"  sheds  of  cotton  mills,  {c)  The  presence  of 
deleterious  gases;  in  mines  carbon  monoxid  and  dioxid, 
carburetted  hydrogen  and  hydrogen  sulphid  may  be  pres- 
ent; in  bleaching  works  sulphur  dioxid  is  evolved,  and 
also  in  copper  works,  though  in  the  latter  it  at  once  passes 
into  the  outer  air.  id)  Vapors  of  hydrochloric,  sulphuric, 
and  nitric  acids,  and  of  chlorin  are  given  off  in  cer- 
tain processes  of  the  manufacture  of  steel,  {e^  Carbon 
disulphid  is  present  in  the  air  of  vulcanized  India-rubber 
works.  (/)  The  fumes  of  phosphorus  in  match-making, 
and  {g)  the  fumes  of  zinc  in  brass  founding;  {Ji)  arsenical 
fumes  in  copper-smelting,  the  preparation  of  wall-paper, 
the  manufacture  of  artificial  flowers,  and  in  the  prepara- 


58  AIR. 

tion  of  skins  for  mounting;  and  (z)  mercurial  vapors 
are  given  off  in  bronzing  and  gilding,  and  in  the  manu- 
facture of  artificial  flowers;  (/)  the  fumes  of  lead  and 
lead  oxid  dust  in  the  manufacture  of  electric  storage- 
batteries. 

Impurities  in  the  Air  of  Dzvellings. — The  impurities 
in  the  air  of  houses  are  those  arising  from  respiration, 
perspiration,  and  combustion,  and,  in  addition,  arsenical 
vapors  may  be  present  when  the  walls  are  covered  with 
paper  containing  arsenic.  In  cities  the  air  of  houses 
may  also  contain  impurities  arising  from  sewers  or  from 
cesspools. 

Dust  in  the  Air. — The  most  injurious  constituent  of 
the  air  in  certain  manufactories  and  in  the  air  of  the 
streets  of  cities  is  dust.  Mineral  dust  is  given  off  in 
certain  manufacturing  processes  and  in  mines.  This  is 
especially  injurious  in  establishments  where  cutlery  and 
files  are  made,  also  in  gun  factories.  Dust  of  vegetable 
origin  is  g-iven  off  in  the  wood-workino-  manufactories. 
The  hard  woods  used  in  cabinet-making  are  especially 
injurious.  In  factories  where  hides  and  feathers  are  used 
dust  of  animal  origin  is  found.  In  the  arrangement  of 
modern  manufacturing  establishments  much  of  the  danger 
from  dust  particles  is  overcome  by  special  arrangements, 
by  means  of  which  the  dust  is  extracted  from  each 
machine  and  is  removed  by  a  special  flue  by  means  of 
a  strong  current  of  air. 

:Examination  of  the  Air  by  the  Senses. — Imme- 
diately on  entering  the  place  where  the  air  is  to  be 
examined,  note  the  condition  of  the  air  as  presented  to 
the  olfactory  sense.  Note  whether  it  is  fresh  and  sweet, 
rather  close,  very  close,  or  fetid.  The  odor  of  animal 
organic  matter  when  present  in  the  air,  even  in  small 
amounts,  is  very  offensive  and  readily  detectable,  if  the 
y?rj/  impression  on  entering  be  noted;  after  half  a  minute 
this  impression  wears  off.  The  readiness  with  which  it 
is  perceived  depends  largely  on  the  humiditv  of  the  air, 
more  so  than  on  the  increase  of  the  temperature.  A  rise 
of  I  per  cent,  in  the  humidity  has  as  much  influence  on 


CHEMICAL  ANAL  YSIS  OF  AIR.  59 

the  condition  of  the  air,  as  judged  by  the  sense  of  smell, 
as  a  rise  of  2.32°  C.  in  the  temperature. 

The  recognition  of  the  presence  of  organic  matter  in 
the  air  is  the  most  important  item  of  information  to  be 
gained  by  the  senses;  but  the  presence  of  ilhiminating- 
gas  or  any  abnormal  smell  should,  of  course,  also  be 
noted,  as  well  as  the  humidity  of  the  air  and  the  pres- 
ence of  notable  quantities  of  dust. 

Chemical  Analysis  of  Air. — This  includes,  first  and 
most  important,  the  determination  of  the  proportion  of 
carbon  dioxid,  since  this  is  commonly  taken  as  an  index 
of  the  other  impurities  in  the  air;  second,  the  estimation 
of  the  humidity  of  the  air;  and,  third,  the  determination 
of  the  quantity  of  oxidizable  organic  matter,  as  shown 
by  the  potassium  permanganate  test.  A  more  complete 
chemical  analysis  would  include  the  estimation  of  the 
amount  of  oxygen  present,  the  amount  of  ammonia  (free 
and  albuminoid),  the  amount  of  nitrous  and  nitric  acids, 
of  hydrogen  sulphid,  etc.,  in  the  air. 

Tlie  proportion  of  carbon  dioxid  in  the  outside  air 
should  alwa3^s  be  determined  at  the  time  when  the  air  of 
an  enclosed  space  is  being  examined.  The  excess  of 
carbon  dioxid  in  the  inside  air  over  that  in  the  outside 
air  is  termed  the  "respiratory  impurity"  of  the  air. 
When,  however,  it  is  impossible  to  analyze  the  outside 
air,  0.4  may  be  taken  as  the  average  content  of  carbon 
dioxid  per  1000  volumes  of  air. 

Estimation  of  Carbon   Dioxid  in  Air It  has  loner  been 

the  custom  to  gauge  the  relative  purity  of  the  atmosphere 
of  confined  spaces  by  the  determination  of  the  proportion 
of  carbon  dioxid  present.  It  has  been  shown  that  all  the 
impurities  of  the  air  arising  from  human  occupation 
increase  in  a  fairly  constant  ratio,  and  that  the  estimation 
of  the  proportion  of  carbon  dioxid  in  such  air  is  indica- 
tive of  the  corresponding  increase  of  the  other  impuri- 
ties, such  as  organic  matter,  ammonia,  moisture,  etc. 
Moreover,  on  account  of  the  relatively  greater  simplicity 
and  accuracy  of  the  methods  of  estimating  the  carbon 
dioxid  the  determination  of  the  carbon  dioxid  content  of 


6o  AIR. 

air  is  generally  employed  in  estimating  the  purity  of  an 

atmosphere. 

The  methods  employed  in  the  laboratory  for  the  esti- 
mation of  the  carbon  dioxid  content  of  air  have  been 
devised  by  von  Pettenkofer.  Of  the  two  methods  devised 
by  von  Pettenkofer,  that  known  as  the  flask  method  is 
the  more  serviceable.  In  both  methods  a  solution  of  cal- 
cium, barium,  or  strontium  hydroxid,  of  definite  strength, 
is  exposed  to  a  known  volume  of  air  in  a  tared  flask  so  as 
to  combine  the  carbon  dioxid  with  the  basic  hydroxid  to 
form  the  corresponding  carbonate.  The  subsequent  titra- 
tion of  a  portion  of  the  alkaline  solution  with  an  acid 
solution  of  known  strength  shows  the  amount  of  the 
alkaline  hydroxid  that  has  been  neutralized  by  combining 
with  the  carbon  dioxid  of  the  air. 

In  the  flask  method  the  air  is  forced  into  a  four-liter 
bottle,  the  capacity  of  which  has  been  accurately  deter- 
mined, by  means  of  a  hand  bellows.  When  the  bottle 
has  been  filled  with  the  air  to  be  examined,  it  is  closed 
with  a  rubber  cap.  The  alkaline  hydroxid  solution  is 
now  introduced  by  carefully  lifting  the  rubber  cap  and 
again  replacing  it.  In  the  von  Pettenkofer  tube  method 
the  alkaline  hydroxid  solution  is  placed  in  a  specially 
constructed  tube  through  which  the  air  to  be  examined 
is  slowly  aspirated. 

When  the  carbon-dioxid  content  of  the  air  is  to  be 
determined  at  points  away  from  the  laboratory  it  is 
desirable  to  use  a  portable  apparatus  such  as  has  been 
devised  for  this  purpose  by  Haldane  or  that  of  Peter- 
son-Palmquist.  These  forms  of  apparatus  permit  one 
to  analyze  only  a  small  sample  of  air,  and  hence  the  results 
are  less  reliable  than  where  larger  samples  are  used,  as 
in  the  Pettenkofer  methods.  Because  of  the  small 
samples  used  extreme  care  is  required  in  the  measure- 
ment of  the  sample  air,  as  well  as  to  avoid  any  changes 
in  the  temperature  of  the  sample  of  air. 

Estimation  of  the  Humidity  of  Air. — The  relative 
humidity  of  the  air  of  a  room  is  most  readily  determined 


CHEMICAL  ANAL  YSIS  OF  AIR. 


6l 


by  means  of  a  sling  psychrometer.  Fairly  satisfactory 
results  can  be  obtained  by  means  of  a  properly  managed 
stationary  psychrometer  (Fig.  3),  or  with  the  hair  hygrom- 
eter (Fig.  4,  p.  39). 

Estimation  of  the  Organic  Matter  in  Air. — The  propor- 
tion of  organic  matter  can  only  be  determined  indirectly, 
either  by  estimating  the  amount  of  oxygen  required  for 
its  oxidation,  or  by  determining  the  amount  of  nitrogenous 


Fig.  5. — Apparatus  required  with  this  method.  It  consists  of:  «,  a  small 
glass  tube,  twenty  centimeters  in  length,  consisting  of  a  narrow  portion  four 
centimeters  long  and  three  millimeters  in  its  internal  diameter,  and  a  dilated 
portion  sixteen  centimeters  long  and  twelve  millimeters  in  its  internal  diameter. 
This  tube  contains  the  granular  pumice-stone  which  serves  as  the  absorbent 
material  in  this  method ;  b,  is  the  gas-meter ;  and  c,  a  Chapman  water  pump. 

organic  matter  from  the  quantity  of  free  and  albuminoid 
ammonia  obtained  through  distillation. 

Thus  far  the  methods  devised  for  the  estimation  of  or- 
ganic matter  in  air  have  not  proved  very  satisfactory. 
One  of  the  principal  reasons  for  this  fact  is  the  necessity 
of  very  careful  manipulation  to  avoid  unusually  large  ex- 
perimental errors.  The  method  which  has  given  most 
satisfactory  results  in  my  hands  ^  is  that  devised  by  Remsen 
(see  Fig.  5),  in  which  the  air  is  aspirated  through  a  small 
glass  tube  containing  freshly  ignited  pumice-stone  which 
has  been  moistened  with  twice-distilled  water.  After  a 
definite  volume  of  the  air  has  been  drawn  through  such  a 
tube,  the  amount  of  organic  matter  adhering  to  the 
pumice-stone  is  determined  either  by  the  Wanklyn  method 
as  free  and  albuminoid  ammonia,  or  by  boiling  with  per- 
^  Smithsonian  Miscellaneous  CoUections,  No.  1037,  1696. 


62  AIR. 

manganate  of  potash  solution  as  in  the  estimation  of 
oxidizable  organic  matter  in  water. 

It  is  often  desirable  to  determine  the  amount  of  dust 
as  well  as  the  nature  of  the  dust  in  air.  A  method 
for  the  enumeration  of  the  dust  particles  in  air  has 
been  devised  by  Aitken,  but  the  method  devised  by 
the  New  York  Commission  on  Ventilation  for  esti- 
mating the  amount  and  nature  of  dust  in  the  air 
has  many  advantages  over  Aitken's  method,  since  it 
permits  the  enumeration  of  the  number  of  dust  particles, 
a  determination  of  their  relative  size,  chemical  com- 
position, as  well  as  the  number  of  bacteria  contained 
in  the  air.  Samples  of  from  looo  to  5000  liters  of  air, 
depending  upon  the  amount  of  dust  contained  in  it, 
may  be  collected,  and  in  this  way  a  fair  estimation  of 
the  condition  of  the  air  may  be  made. 

Diseases  Produced  by  Impure  Air. — Carbon  Dioxid. 
— This  gas  is  poisonous  in  proportions  exceeding  i  or  2 
per  cent. ;  but  there  is  no  doubt  that  the  constant  pres- 
ence of  even  smaller  amounts  for  long  periods  of  time 
induce  a  progressive  depression  of  the  vitality,  thus  con- 
stituting a  preparation  for,  and  a  predisposing  cause  of 
disease.  The  bad  effects  produced  by  breathing  air 
vitiated  by  respiration  are  in  part,  though  not  entirely, 
due  to  the  contained  carbon  dioxid. 

Carbon  Monoxid — This  is  a  powerful  narcotic  poison. 
Its  poisonous  action  depends  on  the  formation  of  a  new 
and  quite  stable  compound  with  the  hemoglobin  of  the 
blood,  the  oxygen  being  entirely  displaced.  It  produces 
unconsciousness,  paralysis  of  the  heart,  and,  at  high  tem- 
peratures, convulsions.  Small  quantities  cause  headache, 
giddiness,  and  speedy  insensibility.  A  mixture  of  carbon 
monoxid  and  dioxid  seems  to  be  more  poisonous  than  the 
monoxid  alone. 

Hydrogen  Sulphid. — This  gas  acts  as  a  narcotic  poison; 
I  volume  per  1000  volumes  of  air  being  fatal  to  dogs.  The 
chronic  effects  produced  by  the  inhalation  of  small  quan- 
tities are  depression,  digestive  disturbances,  and  anemia, 


EFFECTS  OF  VITIA  TED  AIR  GENERALL  Y.       63 

with  narcotic  or  convulsive  symptoms  in  more  acute 
and  severe  cases. 

Effects   of  Vitiated  Air   Generally Vitiation  by 

Respiration  and  Perspiration. — It  is  impossible  to  sepa- 
rate the  effects  produced  by  these  two  forms  of  vitiation 
from  one  another,  nor  is  it  necessary,  as  they  always 
coexist.  In  addition,  the  emanations  from  the  alimen- 
tar}'  tract  are  also  a  possible  source  of  impurity.  The 
effects  produced  by  vitiated  air  of  this  character  may 
be  divided  into  two  classes,  those  of  extreme  vitiation 
acting  for  a  short  time,  and  slighter  vitiation  extending 
over  a  long  period  of  time. 

Extreme  vitiation  for  a  short  time,  as  produced  by 
great  overcrowding,  may  cause  death  from  deficiency  of 
oxygen  and  excess  of  carbon  dioxid  in  the  air  breathed. 
It  was  supposed  until  recently  that  a  large  share  of  the 
effects  produced  by  such  an  atmosphere  was  traceable  to 
the  organic  matter  present  in  expired  air,  but  at  present 
there  is  no  convincing  evidence  that  such  is  the  case. 
On  the  other  hand,  the  experiments  on  animals  indi- 
cate that  deficiency  of  oxygen,  excess  of  carbon  dioxid, 
increased  temperature,  with  high  relative  humidity  of 
the  air,  are  the  principal  factors  in  producing  the  effects. 
The  increased  temperature,  high  relative  humidity,  and 
lack  of  movement  of  the  air  are  the  most  important  fac- 
tors in  producing  the  effects  through  their  operation  upon 
the  heat-regulating  functions  of  the  body. 

Experiments  on  human  beings  confined  in  a  small  air- 
tight chamber  have  demonstrated  that  when  the  degree 
of  vitiation  has  become  sufficiently  great  to  induce 
marked  discomfort  in  the  occupants,  the  discomfort  dis- 
appears very  quickly  when  a  fan  is  set  in  motion  and  the 
air  brought  into  active  circulation.  That  the  discomfort 
is  due  to  interference  with  evaporation  from  the  skin  is 
shown  by  the  fact  that  a  person  confined  in  such  a  room, 
but  breathing  fresh  outside  air,  experiences  an  equal 
degree  of  discomfort  to  those,  in  the  room,  and  by  the  fact 
that  a  person  outside  the  room,  with  his  body  exposed  to 


64  AIR. 

fresh  air  but  breathing  the  air  of  the  room,  experiences 
no  discomfort. 

These  experiments  show  that  vitiated  air  may  be 
breathed  for  a  considerable  time  without  experiencing 
discomfort  or  apparent  injury  so  long  as  the  air  is  kept  in 
motion,  so  as  to  favor  a  sufficient  amount  of  evaporation 
from  the  surface  of  the  body.  If  a  person  were  confined 
in  such  an  atmosphere  for  some  time  the  effect  would,  no 
doubt,  be  highly  injurious. 

Slighter  vitiation  of  the  air  when  continued  for  some 
time  causes  anemia,  weakness,  and  general  depression  of 
the  vital  forces,  nutrition  being  gravely  interfered  with. 
Pulmonary  affections  appear  to  be  produced,  either 
directly  or  indirectly,  by  causing  a  predisposition  to 
them.  Such  conditions  of  the  air  are  met  with  in 
confined  workshops  and  in  overcrowded  schools.  In 
many  instances  the  effects  of  breathing  impure  air  are 
complicated  with  the  sedentariness  of  the  occupation  and 
its  consequent  interference  with  the  normal  functions  of 
the  body;  poverty  and  insufficient  nourishment  being 
frequent  concomitants.  It  is  a  matter  of  fact  that  head- 
ache, malaise,  want  of  appetite  and  of  energy,  are  caused 
by  habitual  breathing  of  impure  air. 

The  prevalence  of  certain  diseases  of  the  lungs  in  those 
constantly  breathing  impure  air  indicates  a  causative 
relation.  The  prevalence  of  phthisis  among  soldiers 
and  sailors  was  considered  to  be  due  to  impure  air  by 
Parkes  and  many  other  competent  observers.  With  the 
improvement  of  the  ventilation  of  their  quarters  phthisis 
has  diminished.  Notwithstanding  the  indications,  im- 
pure air  is  not  directly  the  cause  of  phthisis;  only  indi- 
rectly, through  the  lowered  vitality  it  produces  and  the 
facilities  it  affords  for  the  transmission  of  the  specific 
micro-organism.  The  reduction  in  the  number  of  cases 
of  phthisis  among  soldiers  and  sailors  resulting  from 
improvement  in  the  ventilation  of  their  quarters  is 
brought  about  through  the  increased  vitality  induced, 
and  through  the  greater  dilution  of  the  impurities  in  the 
air — the  tubercle  bacilli — and,  in  consequence,  the  facili- 


EFFECTS  OF  VITIA  TED  AIR  GENERA LL  V.       65 

ties  for  their  transmission  are  less  favorable.  The  preva- 
lence of  pneumonia  also  appears  to  bear  some  relation 
to  the  degree  of  purity  of  the  respired  air.  This  relation 
is  shown  in  the  lowering  of  the  incidence  of  pneumonia 
in  soldiers  where  the  air  space  and  the  ventilation  in 
barracks  has  been  increased.  The  same  favorable 
effects  were  seen  in  laborers  who  had  been  housed  in 
crowded  quarters,  as  in  the  Rand  miners  in  South  Africa. 

Effects    of    Air    Vitiated    by   Combustion Generally 

speaking,  the  gaseous  product^  of  combustion  are  diffused 
so  rapidly  that  there  is  no  prejudicial  effect  on  health; 
but  in  some  instances,  as  in  crowded  work-rooms,  where 
much  gas  is  burned,  and  in  hot,  crowded  places,  such  as 
theaters,  the  effects  are  obvious  and  not  to  be  disregarded. 
The  effects  produced  by  such  air  when  inhaled  constantly 
are  anemia,  vital  depression,  headache,  and  sometimes 
gastric  derangement  when  the  exposure  is  only  for  a 
few  hours. 

In  air  vitiated  by  the  combustion  of  illuminating  gas 
distinct  oppression  is  noticeable  when  the  proportion  of 
carbon  dioxid  has  increased  to  3  to  4  parts  per  1000, 
while  the  addition  of  similar  amounts  of  piire  carbon 
dioxid  to  air  has  no  such  effect  and  is  practically  indis- 
tinguishable from  pure  air.  A  corresponding  deficiency 
in  the  oxygen  of  the  air  is  also  without  sensible  effect. 
In  coal-mines  the  slow  oxidation  of  the  coal  brins^s 
about  an  accumulation  of  carbon  dioxid  to  the  extent  of 
5  to  10  parts  per  1000,  with  a  corresponding  decrease 
in  the  oxygen,  yet  such  air  is  indistinguishable  from  pure 
air.  The  effects  of  air  vitiated  by  combustion  of  illumi- 
nating gas  has  been  traced  to  the  presence  of  sulphur  by 
Dr.  Haldane.  Sulphureted  hydrogen  and  carbon  disul- 
phid  are  contained  in  crude  illuminating  gas  and  may  be 
present  in  the  proportion  of  i  gram  per  cubic  meter  (40 
grains  per  100  cubic  feet),  and  in  such  amounts  exert  a 
distinct  depressing  influence  upon  the  occupants  of  a  room 
illuminated  with  the  gas.  By  passing  the  crude  gas  over 
quicklime,  sulphid  of  lime,  hydrated  oxid  of  iron,  or 
manganese  dioxid,  the  sulphur  compounds  are  absorbed 


66  AIR. 

and  the  purified  gas  contains  only  0.2  gram  of  sulphur 
per  cubic  meter  (8  grains  per  100  cubic  feet). 

Effects  of  Solid  Impurities  in  Air. — The  solid  impuri- 
ties in  the  air  may  produce  irritation  of  the  mucous  mem- 
brane of  the  respiratory  tract  and  lead  to  bronchitis  and 
laryngitis.  The  effects  of  the  solid  impurities  are  most 
frequently  seen  in  those  following  certain  occupations, 
as  in  coal-mining,  cotton-weaving,  emery-grinding, 
polishing  of  metals,   etc. 

In  the  pottery  trade  the  workmen  are  exposed  to  dust, 
and  as  a  result  emphysema  is  quite  common,  and  is 
known  as  "potters'  asthma."  Grinding  of  steel,  espe- 
cially of  the  finer  tools,  is  very  dangerous  unless  wet- 
grinding  is  employed  or  proper  ventilation  is  introduced. 
The  makers  of  pearl  buttons  suffer  from  chronic  bron- 
chitis. In  the  textile  industries  the  fine  particles  of  wool, 
flax,  and  cotton  floating  in  the  air  are  injurious.  The 
makers  of  matches  are  not  infrequent  sufferers  from 
phosphorus-poisoning. 


CHAPTER   II. 
VENTILATION. 

By  the  term  voitilation  we  understand  the  continuous 
introduction  of  pure  air  into  a  room  or  building,  thor- 
oughly mixing  it  with  the  contained  air,  and  the  simul- 
taneous extraction  of  a  like  quantity  of  impure  air.  The 
ventilation  of  rooms  and  buildings  is  necessary  in  order 
to  prevent  the  accumulation  of  the  impurities  of  respira- 
tion, perspiration,  and  combustion. 

Diffusion  of  Gases. — The  principles  employed  in  ordi- 
nary ventilation  depend  upon  a  property  common  to  all 
gases — that  of  diffusion.  Gases  which  have  no  chemical 
affinity  for  each  other  will  mingle  regardless  of  their 
relative  weight  or  density,  and  form  a  perfectly  uniform 
mixture.  The  time  required  for  the  diffusion  of  gases 
is  inversely  proportional  to  the  density,  and  directly  pro- 
portional to  the  square  root  of  the  absolute  temperature. 

Amount  of  Fresh  Air  Required. — Amount  of  Fresh 
Air  Respired. — The  quantity  of  air  taken  into  the  lungs 
by  an  adult  person  at  each  ordinary  inspiration  averages 
500  cubic  centimeters.  Assuming  that  17  inspirations  are 
taken  each  minute,  the  total  amount  of  air  inspired  in 
twenty- four  hours  is  12,240  liters.  About  5  per  cent,  of 
the  oxygen  contained  in  the  inhaled  air  is  absorbed.  If 
17,000  liters  of  air  are  inhaled  in  twenty-four  hours,  850 
liters,  or  1200  grams,  of  oxygen  are  absorbed.  These 
figures  are  based  on  results  obtained  when  a  fair  amount 
of  exercise  is  taken.  A  man  of  averao;e  weight  excretes 
17  liters  of  carbon  dioxid  per  hour  in  repose,  25.5  liters 
with  gentle  exertion,  and  51  liters  with  hard  work. 
Weight  for  weight,  children  give  off  about  twice  as  much 
carbon  dioxid  as  adults. 

67 


68 


VENTILATION. 


The  Standard  of  Purity. — The  air  under  ordinary  con- 
ditions contains  about  0.4  part  of  carbon  dioxid  per  1000 
parts,  and  the  standard  of  purity  for  the  air  of  dwellings 
is  not  to  exceed  0.6  part  in  1000,  thus  allowing  an  excess 
of  0.2  part  per  1000  as  "respiratory  impurity."  The 
amount  of  fresh  air  required  in  order  to  maintain  the 
standard  of  purity  in  the  air  of  dwellings  can  be  very 
readily  determined,  provided  we  know  the  velocity  with 
which  the  air  enters,  the  size  of  the  openings,  and  the 
number  of  persons  in  the  room. 

If  we  take  the  proportion  of  carbon  dioxid  in  the  air 
as  an  index  of  the  character  of  the  ventilation,  the 
method  of  calculating  the  amount  of  fresh  air  required 
to  maintain  the  standard  of  purity  is  based  on  the  follow- 
ing data:  The  amount  of  carbon  dioxid  exhaled  per  head 
per  hour,  and  the  ratio  per  1000  of  respiratory  impurity. 

The  calculation  is  made  according  to  the  formula- —  =  d. 

r 
where 

e  =  the  amount  of  COg  expired,  in  liters,  per  head  per  hour, 
r^  the  ratio  per  looo  of  COj — the  permissible  limit  due  to  respiratory  im- 
purity, and 
d^  the  delivery  of  fresh  air  per  hour,  expressed  in  cubic  meters. 

Example  i :  Let  ^  =  17  liters,  the  average  amount  for  a  mixed  audience  in 
repose,  and  ;'  =  o.2  volume  per  1000,  then  17  -f-  0.2  =  85  cubic  meters  or 
85,000  liters  of  fresh  air  per  head  per  hour. 

Example  2:   With  gentle  exertion  an  adult  man  excretes  25.5   liters  of  car- 

e  2^  ^ 

bon  dioxid  per  hour.      Then  the  formula  _  — -  ^  becomes     -''-'  ^   j^y  c    cubic 

r  0.2  "I"  J 

meters  or  127,500  liters  per  head  per  hour.     It  has  been  found  that  the  amount 

of  air  required  per  hour,  in  liters,  is  as  follows  : 


In  repose. 

Gentle  exertion. 

Hard  work. 

Adult  males     .    .    . 
Adult  females  .    .    . 
Children 

85,000 
57,000 
42,500 

127,500 
85,000 
63,750 

255,000 
170,000 
113,000 

For  muscular  adults  a  larger  amount  of  fresh  air  must 
be  supplied  than  the  average  amounts  given.  A  larger 
amount  should  also  be  supplied  for  the  sick  than  for  the 
healthy ;  an  increase  of  one-fourth  of  the  air-supply  being 


CUBIC  SPACE. 


69 


necessary  for  hospitals,  or  106.25  cubic  meters,  or  106,250 
liters,  per  head  per  hour. 

The  amount  of  carbon  dioxid  given  off  by  school  chil- 
dren may  be  assumed  to  be  10  liters,  for  a  candle  15,  for 
a  petroleum  lamp  60,  and  for  a  gas  flame  100  liters;  con- 
sequently in  artificially  lighted  rooms  additional  space 
must  be  provided  to  prevent  the  accumulation  of  an  ex- 
cess of  carbon  dioxid.  The  amount  of  additional  ven- 
tilation required  for  each  form  of  illumination  can  be 
calculated  in  the  same  manner  as  already  indicated  by 
substituting  the  corresponding  amounts  of  carbon  dioxid 
yielded  b.y  each;  for  instance,  a  gas  flame  would  require 

—  =  </,  where  e  =  100,  instead  of  17,  as  in  the  first  example 
r 

given. 

According  to  Hueppe,  the  degree  of  pollution  of  the 

air  through  different  causes  may  be  determined  by  taking 

into  consideration  the  amount  of  carbon   dioxid,   heat, 

and  watery  vapor  given  off"  by  a  person  or  by  any  of  the 

more  common  sources  of  illumination.     The  necessary 

data  are  contained  in  the  following  table: 


Development  of 

CO2  per  hour 

in  liters. 

Heat 

in 

calories. 

Watery  vapor, 
in  grams 
per  hour. 

Child 

lO.O 
17.0 
20.0 
36.0 

52 

90 

130 

20 

Youth 

Man,  resting 

Man,  working 

40 

60 

130 

15.0 
56-61 
31-56 

90 
109 

106 
430-580 
200-390 
600-875 
800-900 

10-12 

Petroleum  lamp 

Oil  lamp 

Gas  light,  flat  burner    .    .    . 
Gas  light,  Argand  burner    . 

3S-40 

26-40 

130 

157 

Cubic  Space. — The  amount  of  cubic  space  provided 
for  each  person  depends  to  some  extent  on  the  nature  of 
the  occupation,  and  on  the  ease  with  which  the  contained 
air  can  be  replenished.  If  85  cubic  meters  of  fresh  air 
are  to  be  supplied  per  head  per  hour,  it  is  obvious  that 
this  can  be  more  readily  effected  in  a  room  of  25  cubic 
meters  capacity  than  in  one  of  only  half  the  capacity 


70 


VENTILA  TION. 


without  producing  disagreeable  draughts.  The  velocity 
of  the  incoming  air,  the  position  and  size  of  the  inlet 
openings,  as  well  as  the  temperature  of  the  incoming  air, 
must  be  so  regulated  as  to  prevent  the  sensation  of 
draught. 

It  has  been  found  that  in  temperate  climates  the  air  can 
be  changed  satisfactorily  only  about  three  times  an  hour 
unless  it  is  introduced  at  a  temperature  above  i8°  C.  In 
order  that  85  cubic  meters  of  air  may  be  supplied,  the  cubic 
space  for  each  person  should  be  about  one-third  as  large, 
or  28.3  cubic  meters.  For  hospitals  and  sick-rooms  the 
cubic  space  must  be  increased  in  the  same  proportion  as 
in  the  fresh  air-supply  by  about  one-fourth,  so  as  to  pro- 
vide a  space  of  35  to  37  cubic  meters  per  head.  For 
cases  of  infectious  diseases  a  still  larger  space  should  be 
provided.  In  schools,  as  a  rule,  the  cubic  space  provided 
is  very  small  in  proportion  to  the  space  required  theo- 
retically. In  the  schools  of  France  and  England  the  cubic 
space  per  head  ranges  from  2.83  to  4.675  cubic  meters. 
In  the  modern  school  buildings  of  Philadelphia  only  about 
5.6  cubic  meters  are  provided  for  each  pupil,  and  the  air 
is  changed  about  seven  times  an  hour.  With  the  modern 
systems  of  ventilation  now  in  use  this  amount  of  space  is 
possibly  not  much  too  low  to  meet  the  desired  results. 

According  to  Morin,  we  require — 


Amount  of  ventilation 

in  cubic  meters  per 

hour  per  person. 


Maximum 

cubic 

space. 

30 

-50 

2 

5 

30 

-qo 

15 

-25 

20 

-25 

15 

-30 

7-5 

-10 

12 

-15 

For  hospitals         

For  prisons 

For  factories 

For  barracks 

For  theaters 

For  halls  and  assembly-rooms 

For  schools 

For  class-rooms  for  adults  .    . 


60-100 

50 
60-100 
30-  50 
40-  50 
30-  60 
15-  20 
25-  30 


It  will  be  noted  that  Morin  allows  for  a  complete 
change  of  air  only  twice  each  hour.  Where  more  fre- 
quent changes  of  air  can  be  definitely  secured  a  smaller 


NATURAL  VENTILATION.  71 

amount  of  cubic  space  per  person  may  give  satisfactory 
results. 

General  Rules  for  Ventilation. — The  quality  of  the 
incoming  air  is  of  equal  importance  with  the  quantity; 
therefore,  care  must  be  exercised  in  selecting  the  source 
of  the  air-supply.  In  large  towns  it  may  be  necessary  to 
wash  or  filter  the  air  before  it  is  distributed. 

The  current  of  incoming  air  should  be  imperceptible. 
This  is  of  special  importance  when,  as  is  generally  the 
case,  the  temperature  of  the  outside  air  is  lower  than  that 
of  the  air  of  the  building.  When  cold  draughts  are  pro- 
duced the  system  of  ventilation  is  faulty.  The  larger  the 
area  of  the  inlet  and  the  outlet  openings  the  slower  the 
velocity  of  the  air  current,  but  obviously  these  openings 
cannot  be  enlarged  indefinitely. 

The  fresh  air  must  not  only  be  supplied  to  a  space,  but 
it  must  also  be  difiused  equably  throughout  the  space,  so 
as  not  to  pass  directly  from  the  point  of  entrance  to  the 
point  of  exit.  It  is  very  difficult  practically  to  attain 
this  end,  but  unless  it  is  attained  we  fail  to  secure  the 
proper  displacement  and  renewal  of  the  vitiated  air. 

Ventilation  is  effected  either  by  natural  means  or  by 
the  aid  of  mechanical  contrivances.  The  former  is  called 
natural  ventilation  and  the  latter  artificial  ventilation. 

Natural  Ventilation. — In  all  buildings  there  is  an 
interchange  between  the  inside  and  outside  air  by  diffu- 
sion through  the  substance  of  the  walls  and  floors  them- 
selves, but  this  interchange  is  insufficient  to  replenish  the 
contained  air,  and  provision  must  be  made  to  supply  the 
necessary  amount  of  fresh  air  through  openings  in  the 
walls,  as  doors,  windows,  etc.,  or  through  special  open- 
ings into  ventilating  shafts;  the  latter  method  being  the 
preferable  one,  especially  for  large  assembly-halls  and 
school-rooms. 

The  forces  which  are  continually  acting  in  nature  and 
produce  natural  ventilation  are  diffusion,  the  action  of  the 
wind,  and  the  difference  in  density  of  masses  of  air  of  dif- 
ferent temperatures;  the  latter  being  the  most  important. 


72  VENTILA  TION. 

Diffusion. — All  gases,  including  the.  mixture  of  oxy- 
gen and  nitrogen  which  constitutes  atmospheric  air,  dif- 
fuse through  space,  the  force  of  the  diffusion  being 
inversely  as  the  square  roots  of  the  densities  of  the  gases. 
The  diffusion  of  carbon  dioxid,  and  the  other  gaseous 
impurities  in  the  air  of  an  enclosed  space,  into  the  fresh 
air  takes  place  not  only  through  the  natural  openings  of 
rooms,  as  doors,  etc.,  but  also  through  the  walls,  floor, 
and  ceiling,  because  the  materials  of  which  these  are 
constructed  are  always  more  or  less  porous  and  perme- 
able. The  amount  of  ventilation  through  walls  varies 
with  the  porosity  of  the  materials  of  which  they  are 
formed;  the  temperature  of  the  inside  and  outside  air; 
the  force  and  direction  of  the  wind,  etc.  Damp  walls 
are  less  porous  than  dry  walls,  and  this  is  partly  the 
cause  of  the  unhealthfulness  of  damp  houses. 

The  Action  of  the  Wind. — This  is  exerted  in  two  ways: 
(i)  By  perflation — that  is,  blowing  through  an  air  space 
and  thus  changing  the  air  contained  therein;  and  (2)  by 
aspiration — that  is,  sucking  up  masses  of  air  in  conse- 
quence of  a  partial  vacuum  that  is  produced  on  either 
side  of  a  moving  mass  of  air.  Perflation  takes  place 
through  doors  and  windows,  as  well  as  through  walls 
and  ceilings.  In  the  wards  of  a  hospital,  where  thorough 
ventilation  is  of  especial  importance,  the  windows  should 
be  placed  on  both  sides  of  the  room,  so  as  to  allow  full 
sway  to  the  perflating  action  of  the  wind.  Aspiration  is 
provided  when  the  wind  blows  over  the  top  of  a  chimney 
or  ventilating  shaft  and  causes  an  upward  current  at  right 
angles  to  its  course.  A  strong  wind  may  impede  the 
movement  of  the  air  up  the  chimney.  Down  draught 
may  be  produced  and  smoke  forced  into  the  rooms. 

Difference  in  Temperature. — The  movement  produced 
by  the  difference  in  weight  of  masses  of  air  of  different 
temperatures  is  the  chief  force  acting  in  natural  ventila- 
tion. When  a  mass  of  air  is  heated  it  expands,  and  pro- 
portionate volumes  of  it  become  lighter  ;  consequently  it 
rises  to  a  higher  plane  and  is  displaced  by  colder  and 


ARRANGEMENTS  IN  NATURAL    VENTILATION.     J2> 

heavier  air.  The  greater  the  difference  in  the  tempera- 
ture of  masses  of  air  the  more  rapid  the  movement  that 
is  produced.  The  rate  of  movement  may  be  calculated 
according  to  either  of  the  following  rules: 

1.  The  velocity  of  falling  bodies  is  equal  to  the  square 
root  of  the  space  or  height  through  which  they  have 
fallen,  multiplied  by  the  square  root  of  twice  the  accel- 
erating force  of  gravity.      V=  \/  2gs. 

2.  Rule  of  Montgolfier:  Fluids  pass  through  an  orifice 
in  a  partition  with  a  velocity  equal  to  that  which  a  body 
would  acquire  in  falling  through  a  space  or  height  equal 
to  the  difference  in  depth  of  the  fluids  on  the  two  sides 
of  the  partition. 

All  gases  under  constant  pressure  expand  equally. 
If  V=  the  volume  at  o°  C,  then  the  volume  at  /°  =  Fx 
(i  +  «  .  2"),  where  a  =  0.003665.  The  effect  of  heat  on  air, 
therefore,  is  to  increase  its  volume  and  to  lessen  its  den- 
sity directly  in  proportion  to  the  increase  in  temperature. 

Arrang-ements  in  Natural  Ventilation. — In  cold  and 
temperate  climates  the  openings  that  are  usually  present 
in  inhabited  rooms  are  doors  and  windows.  Chimneys 
are  also  generally  present.  Ventilation  is  not  the  primary 
object  of  these  openings,  but  nevertheless  they  act  as 
ventilators,  and  in  very  many  instances  they  afford  the 
only  means  for  ventilation.  Diffusion  takes  place  through 
all  these  openings,  as  well  as  through  the  walls,  floors, 
and  ceilings,  and  generally  no  special  arrangements  are 
needed  to  assist  it  in  ordinary  dwellings. 

The  natural  ventilation  through  the  pores  of  the  walls 
is  of  slight  significance.  It  occurs  constantly  in  a  vertical 
direction  through  the  floor  and  ceiling.  In  winter,  when 
the  house  is  heated,  it  occurs  from  below  upward,  and  in 
summer  in  the  opposite  direction,  because  the  house  is 
colder  than  the  outside  air.  Along  the  side  walls  the 
excess  of  pressure  diminishes  from  the  floor  to  the  ceil- 
ing, between  which  points  there  is  a  neutral  zone  where 
it  is  zero.  In  winter,  in  consequence  of  warming  the 
room  air,  there  is  an  outward  movement  above  this  zone, 


74 


VEJSTTILA  TlON. 


and  below  it  an  inward  movement  of  cold  outside  air 
(see  Fig.  6)  ;  the  reverse  takes  place  when  the  room  is 
colder  than  the  outside  air  (see  Fig.  7). 

The  perflating  action  of  .the  wind  must  be  utilized  and 
regulated.     Open  doors  and  windows  allow  the  entrance 

CoCcL^ 

1 


Cold' 


'CoU 


of  moving  masses  of  air,  but  if  the  movement  is  of  suffi- 
cient rapidity  to  produce  perceptible  currents  the  doors 
and  windows  will  probably  be  closed  and  the  perflating 


Warm 


action  of  the  wind  arrested.  The  windows  should  always 
be  placed  on  opposite  sides  of  a  room  to  secure  free  per- 
flation and  thorough  change  of  the  air.  Even  if  this  can 
be  secured  only  at  intervals,  it  is  of  special  importance  in 
the  ventilation  of  wards  of  hospitals  and  of  school-rooms. 


ARRANGEMENTS  IN  NA  TURAL   VENTILA  TION.    75 


If,  however,  some  arrangement  is  made  by  which  fresh 
air  may  be  brought  into  a  room  without  having  the  cur- 
rent impinging  directl}-  upon  the  occupants,  the  air  of 
the  room  can  be  renewed,  to  a  great  extent,  through  the 
force  of  the  wind.  A  simple  plan  by  which  this  can  be 
accomplished  is  to  have  the  upper  sash  incline  inward, 
leaving  a  space  at  the  top  through  which  air  may  enter, 
so  as  to  direct  the  current  of  air  upward  toward  the  ceil- 
ing, where  it  is  distributed  to  all  parts  of  the  room  and 
slowly  falls  and  displaces  the  contained  air.  Another 
plan  is  to  place  a  narrow  board  beneath  the  lower  sash, 
so  as  to  raise  its  upper  edge  above  the  level  of  the  bottom 
of  the  upper  sash  and  form  an  opening  between  the 
two  sashes,  through  which 
the  air  may  enter  (Fig.  8). 
By  this  arrangement  the  en- 
tering current  of  air  is  also 
deflected  upward  toward  the 
ceiling.  The  same  results 
may  also  be  obtained  by 
placing  a  louver  near  the 
top  of  the  upper  sash ;  or 
by  placing  a  movable  glass 
disk,  perforated  with  holes, 
over  one  of  the  panes,  which 
is  perforated  in  a  similar 
manner,  when  by  rotating 
the  disk  communication  can 
be  made  with  the  outside 
air  whenever  desired. 

Inlet  openings  in  the  walls 
to  utilize  the  perflating  action  of  the  wind  may  be  either 
direct  openings  through  the  walls  by  using  "  air  bricks," 
or  valved  openings,  as  the  Sherringham  valve,  in  which, 
instead  of  the  air  brick,  an  iron  frame,  containing  a 
movable  plate  or  valve  on  its  inner  surface,  is  inserted 
into  the  opening.  When  the  valve  is  open,  it  directs  the 
current  of  air  upward  toward  the  ceiling.     It  is  easily 


iiiiii 

Fig.  S. — Window  ventilator. 


76 


VENTILATION. 


closed  by  reason  of  a  well-adjusted  counterbalanced 
weight.  These  latter  arrangements  are  frequently  em- 
ployed in  connection  with  what  is  known  as  the  direct- 
indirect  system  of  heating  (Fig.  9). 

Perflation  may  be  aided  by  cowls  attached  to  the  tops 
of  ventilating  shafts.  The  cowls  are  composed  of  two 
tubes,  one  within  the  other,  having  a  hooded  cover  with 
one  large  opening,  at  right  angles  to  the  mouth  of  the 
shaft,  which  is  turned  toward  the  point  from  which  the 


Fig.  9. — Wall  air  inlet. 


Fig.  10. — Cowl. 


wind  is  coming  and  directs  its  current  downward  through 
one  of  the  tubes.  They  may  be  either  movable  or  fixed  ; 
the  latter  being  the  preferable  form,  because  it  is  less 
liable  to  get  out  of  order.  The  best  form  of  cowl  con- 
sists of  a  fixed  downcast  tube  with  expanded,  trumpet- 
shaped  mouth,  above  which  is  a  conical  cap,  the  apex  of 
which  is  turned  upward  (Fig.  10).     With  this  arrange- 


ARRANGEMENTS  IN  NATURAL   VENTILATION.    77 


ment  the  aspirating  force  of  the  wind  may  be  utilized  to 
maintain  a  fairly  constant  current  of  air. 

The  movement  produced  by  the  unequal  weights  of 
masses  of  air  of  different  temperatures  takes  place  through 


Fig.  II. — Ail-  introduced  at  bottom,  discharged  at  top. 

the  ordinary  openings,  and  to  some  extent  through  the  por- 
ous walls  of  a  room;  but,  as  the  doors  and  windows  may  be 
closed  and  the  movement  be  largely  arrested,  other  open- 
ings should  be  provided  to  secure  ventilation.  The 
problem  to  be  solved  is — Which  is  the  most  satisfactory 


Fig.  12. — Air  introduced  on  side,  discharged  at  top. 

location  for  an  outlet  through  which  the  vitiated  air 
of  an  enclosed  space  may  readil}'  escape,  and  an  inlet 
through  which  the  fresh  outside  air  may  enter  without 
causing  a  perceptible  draught  ?  The  expired  air  of  human 
beings  is  warmed  to  within  about  one  degree  of  centigrade 
of  the  body  temperature,  and  consequently  it  rises  into 


78 


VENTILA  TION. 


the  upper  part  of  the  enclosed  space.  The  air  surround- 
ing the  bodies  of  the  occupants  is  also  warmed  to  some 
extent,  and  rises  into  the  upper  part  of  the  space.  These 
facts  indicate  that  the  proper  place  for  the  outlet  openings 


Air  introduced  on  side,  discharged  on  opjiosite  side. 


is  in  or  near  the  ceiling.  If  artificial  lighting  is  used^ 
the  air  is  heated  as  the  result  of  the  combustion  and  rises 
into  the  upper  part  of  the  space.  This  fact  also  indi- 
cates that  the  outlet  openings  should  be  placed  in  or  near 
the  ceiling,  so  as  to  allow  air  vitiated  in  this  manner  to 


Fig.  14. — Air  admitted  on  side,  discharged  near  bottom. 


escape  as  freely  as  possible,  and  to  prevent  it  from  ming- 
ling with  the  air  that  is  to  be  respired. 

With  the  outlet  openings  at  the  top  of  the  enclosed 
space,  the  inlet  openings  should  be  at  a  lower  level,  pref- 
erably as  near  the  floor  as  possible,  in  order  to  secure  the 
greatest  advantage  possible  from  differences  in  density  of 


ARRANGEMENTS  IN  NA  TURAL  VENTILA  HON.     79 

masses  of  air,  by  making  the  height  of  the, column  of 
heated  air  as  great  as  possible.  A  current  of  cold  air 
introduced  at  the  level  of  the  feet  of  the  occupants  would 
be  unbearable,  and  various  plans  have  been  devised  to 


Fig.  15. — Air  admitted  at  bottom,  discharged  near  bottom. 

obviate  this  difficulty,  but  in  practice  none  of  them  has 
proved  entirely  satisfactory. 

Some  experiments  were  made  by  Mr.  Warren  R.  Briggs, 
of  Bridgeport,  Conn.,^  on  the  subject  of  the  proper 
method  of  introducing  pure  air  into  rooms,  and  the  best 
location  for  the  inlet  and  outlet.     The  experiments  were 


Fig.  16. — Inlet  near  top,  discharge  near  bottom. 

conducted  with  a  model  having  about  one-sixth  the 
capacity  of  a  school-room  to  which  the  perfected  system 
was  to  be  applied.  The  movements  of  the  air  in  the 
model  of  the  building  were  made  visible  by  mingling 

1  Carpenter's  Heating  and  Ventilation  of  Buildings,  p.  49. 


8o  VENTILA  TION. 

smoke  with  the  inflowing  air-stream,  which  made  the 
movements  of  the  air  visible. 

The  results  of  the  experiments  are  shown  graphically 
in  Figs.  II  to  1 6.  In  each  case  the  distribution  of  the 
fresh  air  is  indicated  by  the  curved  lines  of  shading.  A 
study  of  these  sketches  is  very  suggestive,  as  it  indicates 
the  best  results  when  the  inlet  is  on  the  side  near  the 
top,  and  the  outlet  is  at  the  bottom  and  near  the  center 
of  the  room.  The  tendency  of  the  entering  air  to  form 
direct  currents,  which  in  some  instances  tend  to  pass  out 
without  perfect  diffusion,  is  well  shown.  This  tendency 
is  less  as  the  velocity  of  the  entering  air  is  reduced,  and 
we  probably  get  nearly  perfect  diffusion  in  every  case 
where  the  outlet  is  well  below  that  of  the  inlet,  provided 
the  velocity  of  the  entering  air  is  low — less  than  1.2 
meters  per  second. 

In  order  to  prevent  the  formation  of  draughts  in  the 
ventilation  of  rooms,  the  movement  of  the  incomitjg  air 
must  be  slow  and  gentle,  it  must  be  agreeable  in  temper- 
ature, and  its  humidity  must  not  be  too  great  nor  too  low. 
The  conditions  which  cause  draught  are  (i)  too  great 
rapidity  of  current,  (2)  too  low  a  temperature,  (3)  exces- 
sive or  (4)  insufficient  humidity  of  the  air. 

With  regard  to  the  size  of  inlets  and  outlets,  the  condi- 
tions of  temperature  are  so  variable  that  it  would  be  im- 
possible to  fix  a  size  that  would  be  universally  applicable. 
As  an  average  for  the  temperate  zone,  a  size  of  156  square 
centimeters  per  head  for  inlet,  and  the  same  for  outlet, 
seems  calculated  to  meet  common  conditions;  but  arrange- 
ment should  be  made  for  enabling  this  to  be  lessened  in 
very  cold  weather,  or  if  the  influence  of  very  strong 
winds  is  felt.  Each  opening  should  not  be  larger  than 
300  to  400  square  centimeters.  Air  expands  on  being 
warmed,  but  it  is  unnecessary  to  have  a  larger  outlet  area 
than  the  inlet  area;  indeed,  one  of  the  best  ways  of  pre- 
venting draught  is  to  ensure  greater  facility  for  entrance 
than  for  exit  of  the  air.  The  shape  of  the  opening  of 
the  inlet  or  outlet  tube  that  causes  least  friction  is  the 


ARTIFICIAL   VENTILATION. 


8i 


circular,  inasmuch  as  the  area  is  larger  in  proportion  to 
the  periphery  than  that  of  any  other  figure. 

Friction. — Some  degree  of  friction  is  inevitable,  and  a 
deduction  of  one-fourth  should  be  made  in  every  case  on 
this  account.  In  addition  to  this,  a  further  loss  of  ve- 
locity arises  from  the  following  causes:  Size  of  the  open- 
ing, shape  of  the  opening,  length  of  the  shaft,  angles  in 
the  shaft,  and  the  presence  of  dirt. 

The  velocity  of  the  air-current  is  readily  determined 
by  means  of  an  anemometer  (Fig.  17).  If  we  know  the 
size  of  the  ventilating  shaft  and  the  velocity  of  the  air- 


FiG.  17. — Portable  anemometer. 

current,  we  can  readily  ascertain  the  amount  of  fresh  air 
supplied. 

Artificial  Ventilation. — By  artificial  ventilation  is 
meant  that  form  of  ventilation  in  which  movement  of 
air  is  induced  by  artificial  contrivances.  These  are, 
broadly,  of  two  kinds :  Heat  and  mechanical  means,  and 
either  of  these  may  be  arranged  for  extraction  of  foul  air 
or  propulsion  of  fresh  air,  the  former  being  sometimes 
called  the  vacuum,  the  latter  the  plenum  system. 

Heat. — In  practice  heat  is  employed  usually  to  produce 

ventilation  by  extraction,  not  by  propulsion.     The  more 

common  application  of  heat  in  artificial  ventilation  is  in 

the  extraction  of  air  from  a  room  through  the  ordinary 

6 


82  VENTILA  7 ION. 

open  fireplaces  and  chimneys.  This  action  depends  on 
the  principle  already  treated  of  under  natural  ventilation 
— that  of  expansion  of  masses  of  heated  air  causing  the 
production  of  upward  currents. 

The  rate  of  flow  up  an  ordinary  chimney  varies  from  i 
to  2  meters  per  second.  Taking  the  ordinary  size  of  a 
flue  as  24  by  36  centimeters,  it  is  seen  that  the  discharge 
varies  between  310  and  620  cubic  meters,  a  quantity 
sufficient  for  3  to  6  persons.  The  movement  of  the  air 
will  be  toward  the  fire  from  all  the  openings  in  the  room, 
which,  if  the  fire  burn  briskly,  are  converted  into  inlet 
openings.  The  larger  the  fireplace  and  the  fire,  the 
greater  the  extractive  force. 

A  heated  column  of  air  may  also  be  produced  by  placing 
coils  of  hot-water  pipes  or  steam  pipes  or  gas-burners  in 
a  ventilating  shaft.  Whatever  be  the  source  of  heat,  it  is 
best  to  place  it  at  the  bottom  of  the  shaft,  and  not  at  the 
top.  In  places  where  a  central  lighting  arrangement  is 
adopted,  as  in  the  auditorium  of  theaters,  advantage  may 
be  taken  of  the  heat  given  oS"  by  the  illuminating  agent 
to  carry  off"  the  impure  air  through  a  shaft  placed  above 
the  chandelier. 

The  great  disadvantage  of  extraction  by  heat  is  its 
irregularity  of  action.  It  is  almost  impossible  to  regu- 
late the  temperature  of  the  column  of  heated  air,  conse- 
quently the  upward  current  will  sometimes  be  far  more 
rapid  than  at  other  times.  It  is  also  costly  on  a  large 
scale.  Nevertheless,  the  ventilating  power  of  the  com- 
mon open  fireplace  is  so  great  that  it  is  a  most  valuable 
method  of  ventilation. 

Mechanical  Aids. — These  are  chiefly  fans,  pumps,  and 
jets.  Fans  are  almost  always  rotary,  and  may  be  either 
centrifugal  or  axial  (Fig.  18).  The  efficiency  of  a  fan  is 
estimated  in  terms  of  the  volume,  velocity,  and  pressure 
of  the  induced  air-current  compared  with  the  horse-power 
required  to  produce  it.  Axial  fans  are  more  suitable 
where  a  large  volume  at  low  pressure  and  velocity  is  re- 
quired ;  centrifugal  fans,  for  the  production  of  high  ve- 
locity and  high  pressure.     A  large  fan  operated  at  low 


ARTIFICIAL   VENTILATION. 


83 


speed  is  more  economical  than  a  small  one  at  high  speed. 
The  blades  are  best  curved  in  centrifugal,  flat  and  in- 
clined in  axial,  fans.  Fans  can  be  used  either  for  extrac- 
tion or  propulsion  ;  they  may  be  operated  by  steam,  wind, 
water,  or  electricity.  The  amount  of  air  delivered  by  a 
centrifugal  fan  can  be  calculated  by  taking  the  velocity 
of  revolution  of  the  periphery  of  the  fan ;  three-fourths 
of  this  equals  the  velocity  of  the  air,  this  allowance  being 


Fig.  18. — Air  propeller,  with  electric  motor  attached. 

necessary  on  account  of  friction.  The  sectional  area  of 
the  conduit  being  known,  the  delivery  per  second  can  be 
calculated  from  these  data. 

Pumps  are  employed  in  the  ventilation  of  mines,  and 
may  be  used  either  for  forcing  in  fresh  air  or  extracting 
foul  air.  They  are  seldom  employed  in  the  ventilation 
of  buildings. 

Jets  for  producing  currents  of  air  are  of  three  kinds — 
steam,  compressed  air,  and  water.  Their  efficiency  de- 
pends principally  upon  the  degree  of  pressure  at  which 
the  jets  issue  from  the  nozzle.  All  jets  are  apt  to  be 
noisy,  compressed  air  being  least  so.     They  can  be  used 


84  VENTILATION. 

either  for  extraction  or  propulsion ;  in  the  latter  case  the 
steam  jet  will  moisten  the  incoming  air  considerably, 
which  may  be  either  an  advantage  or  the  reverse. 

Arrangements  for  Artificial  Ventilation. — There  are 
certain  points  that  require  attention  in  all  arrangements 
for  artificial  ventilation: 

(i)  The  point  of  intake  for  the  fresh  air  should  be 
selected  principally  for  the  purity  of  the  air  obtained, 
and,  as  a  general  rule,  the  purest  air  will  be  found  at  a 
height  of  3  to  4. 5  meters  (10  to  15  feet)  from  the  ground. 

(2)  The  air  may  require  cleansing  or  filtering.  With 
this  object  in  view  it  may  be  made  to  impinge  on  a  sheet 
of  still  water  or,  better,  a  film  of  glycerin,  which  retains 
impurities  better  and  does  not  evaporate  so  readily. 
The  air  may  be  filtered  through  coarse  cloth  or  cotton, 
the  latter  being  most  effective,  but  requires  frequent 
renewal.  A  thickness  of  about  1.4  decimeters  (6  inches) 
may  be  employed.  The  air  may  also  be  purified  by 
washing  it  with  a  spray  of  water  or  passing  it  through  a 
wire  screen  over  which  a  fine  stream  of  water  is 
running.  This  adds  moisture  to  the  air  and  may  require 
supervision,  as  hot,  moist  air  produces  languor. 

(3)  The  temperature  of  the  incoming  air  should  be 
regulated.  It  may  be  cooled  in  summer  by  passing  over 
ice,  or,  if  the  water  spray  is  used,  this  may  be  cooled  by 
ice,  which  is  an  effective  method  of  reducing  the  tem- 
perature. An  apparatus  devised  by  Professor  Gates,  of 
Washington,  for  the  cooling  of  rooms  in  summer,  can  be 
more  cheaply  operated  than  a  coal  stove  in  winter.  ^  It  is 
simply  a  tall  cylinder  of  galvanized  iron  resting  in  a  large 
basin  or  pan,  and  connecting  at  the  top  with  the  ordinary 
stove  pipe  or  with  a  tube  leading  out  of  a  window.  In 
the  top  of  the  cylinder's  interior  is  a  perforated  tubular 
ring,  and  on  a  cock  being  turned  on  this  ring  an  artificial 
shower  is  produced  inside  the  cylinder.  The  water  thus 
flowing  down  the  sides  takes  on  a  rapid  spiral  motion 
which  sucks  the  air  down  the  cylinder  at  a  rapid  rate; 
the  fine  spray  inside  cooling  the  air,  reducing  its  hu- 
midity to  normal,  and  purifying  it  of  all  dust  and  odor. 


ARTTFTCTAL   VENTILATION.  85 

The  water  collects  in  a  basin  below,  from  which  it  is 
drained  off,  the  cool  air  escaping  through  openings  just 
above  the  water  surface  of  the  basin.  In  some  experi- 
ments made  with  this  apparatus  the  temperature  of  the 
air  on  entering  the  cooling  cylinder  was  observed  to  be 
33°  C,  while  it  was  20°  C.  on  taking  its  exit  at  the 
bottom.  Recently  "liquid  air"  has  been  introduced  as 
a  means  of  cooling  the  air,  and  has  been  applied  with 
satisfaction  in  the  ventilation  of  theaters. 

The  incoming  air  may  be  warmed  by  passing  over  or 
through  a  heating  apparatus,  such  as  hot-water  or  steam 
pipes.  This  is  the  method  now  commonly  employed  in 
the  ventilation  of  large  buildings.  The  whole  of  the 
air-supply,  in  a  scheme  of  artificial  ventilation,  ought  to 
be  admitted  at  the  required  temperature  to  the  chamber 
to  be  ventilated,  and  no  attempt  should  be  made  to 
warm  the  room  by  superheated  air.  As  a  rule,  the  fresh 
air  should  be  warmed  as  nfear  as  possible  to  the  tempera- 
ture desired  in  the  room.  In  large  buildings,  consisting 
of  many  rooms,  the  scheme  of  ventilation  requires  sepa- 
rate and  perhaps  different  arrangements  in  different  por- 
tions. In  other  buildings,  such  as  churches  and  theaters, 
a  single  central  scheme  is  preferable. 

(4)  The  channels  through  which  the  air  is  conducted 
should  be  so  arranged  as  to  be  easily  cleansed ;  this  is 
especially  necessary  in  propulsion  methods,  and  inatten- 
tion to  this  point  has  in  many  instances  brought  the 
method  into  disrepute.  Where  the  air  has  been  pre- 
viously filtered  there  will,  of  course,  be  less  deposit  of 
dust  on  the  sides  of  the  inlet  shafts.  Extraction  shafts 
also  require  to  be  kept  clean. 

The  inlet  and  outlet  openings  must  be  so  placed  that  a 
thorough  aeration  of  the  room  is  possible  without  the 
production  of  draughts.  Different  arrangements  are 
required  for  the  inlet  and  outlet  openings  for  winter  and 
summer.  In  summer  the  cool  air  is  brought  in  at  a 
height  of  from  2  to  3  meters  above  the  floor  in  such  a 
manner  that  it  is  conducted  toward  the  ceiling.  From 
this  point  it  sinks  gradually,  and  when  warmed  rises  and 


86 


VENTILA  TION. 


takes  its  exit  at  the  opposite  side  of  the  room  near  the 

ceilinof.     In  winter  the  air  takes  its  exit  near  the  floor. 

The  system  of  ventilation  should  be  so  constructed 
that  it  can  be  regulated  to  meet  all  reasonable  require- 
ments as  to  quantity  of  air  furnished  and  the  temperature 
that  may  be  demanded  by  atmospheric  conditions. 

Removal  of  Dust. — The  removal  of  dust  in  factories 
requires  special  arrangements.     The  circulation  of  air  in 


Fig.  19. — Apparatus  for  removing  dust  in  manufacturing  establishments : 
a,  inlet  to  exhaust  shaft ;  b,  valve  regulating  spray ;  c,  water-supply  pipe ;  d^ 
outlet  of  exhaust  shaft. 

closed  rooms  is  insufiEicient  to  keep  the  dust  from  settling, 
and,  especially  in  factories,  special  arrangements  for  its 
removal  are  required.  Where  large  quantities  of  dust  are 
produced,  as  in  certain  factories,  it  is  often  possible  to 
apply  a  strong  air  current  near  the  source  of  the  dust  in 
order  to  aspirate  it,  as  in  the  case  of  circular  saws  and 
grindstones  (Figs.  19,  20,  21).  Where  the  dust  cannot 
be   satisfactorily  removed  by  such  a  method  it  is  often 


REMOVAL  OF  DUST. 


87 


possible  to  modify  the  manufacturing  process  so  as  to 
prevent  excessive  dust  formation.  The  use  of  a  spray  of 
water  so  as  to  render  the  material  damp  and  thus  prevent, 


rN     W^ 


Fig.  20. — Apparatus  for  removing  dust  in  manufacturing  establishments : 
a,  emery  wheel ;  b,  hood  over  emery  wheel ;  c,  exhaust  shaft. 


Fig.  21. — Apparatus  for  removing  dust  in  manufacturing  establishments ; 
a,  blower;  3,  dust-collecting  chamber;  <:,  water-sprays. 


88  VENTILA  TION. 

in  large  part,  the  formation  of  dust  will  aid  in  keeping 
the  air  pure. 

In  houses  and  hospitals  dust  is  to  be  prevented  as  much 
as  possible.  If  dust  has  formed,  it  tends  to  settle  upon 
horizontal  surfaces,  and  should  be  removed  with  damp 
cloths. 

Comparison  of  Extraction  and  Propulsion  Methods. — 
The  extraction  method  is  less  costly  and  utilizes  the 
naturally  high  temperature  of  the  vitiated  air.  Its  dis- 
advantages are  that  the  source  of  the  incoming  air  is  not 
under  control,  and,  consequently,  impure  air  may  be  ad- 
mitted and  there  is  greater  liability  to  draught.  In  the 
propulsion  method  the  inlets  are  entirely  under  cofitrol 
if  properly  arranged,  and  the  purity  of  the  air  can  be 
assured,  as  well  as  its  suitable  temperature  and  velocity, 
so  as  to  avoid  draughts.  A  proper  diffusion  of  the  in- 
coming air  throughout  the  room  is  more  easily  effected 
in  the  propulsion  than  in  the  extraction  method.  The 
disadvantage  of  propulsion  is  its  greater  cost.  A  combi- 
nation of  the  two  methods  is  frequently  employed,  and 
meets  all  the  requirements. 

Comparison  of  Natural  and  Artificial  Methods. — (i) 
Natural  ventilation  is  rarely  sufficient,  and  usually  re- 
quires to  be  supplemented.  (2)  For  dwellings,  extraction 
by  heat  by  means  of  open  fireplaces  and  chimneys  is  gen- 
erally sufficient.  It  is  automatic  and  requires  no  special 
attention,  but  it  is  not  a  perfect  system  of  ventilation. 
(3)  For  large  halls,  churches,  theaters,  and  schools  arti- 
ficial ventilation  is  necessary.  In  buildings  of  this  char- 
acter mechanical  methods  have  a  decided  advantage  over 
natural  ventilation,  not  only  in  the  greater  purity  of  the 
air,  but  in  the  more  equable  temperature  attainable. 

Hutnidifyingr  the  Air. — The  air  of  houses  is 
frequently  very  dry  during  the  colder  months  of  the 
year  owing  to  the  reduction  of  the  relative  humidity 
of  the  air  simply  by  raising  its  temperature  and  thus 
raising  its  ability  to  take  up  moisture.  If  the  temper- 
ature of  the  outside  air  is  0°  C.  and  its  relative  humidity 


HUMIDIFYING   THE  AIR.  89 

100  per  cent.,  the  fact  that  the  air  is  warmed  to  20°  C. 
while  passing  through  the  heating  plant  causes  the 
relative  humidity  to  fall  to  38  per  cent.,  since  air  at  0°  C. 
when  saturated  holds  4.90  gm.  of  water  per  kilogram, 
while  at  20°  C.  it  could  hold  12.74  §i^- 

In  order  to  increase  the  relative  humidity  of  the  air 
in  heated  houses  various  plans  have  been  suggested  to 
add  moisture  to  the  air.  In  furnace-heated  houses  a 
shallow  pan  of  water  is  placed  in  the  bottom  of  the  heater, 
but  this  is  not  very  effective  because  only  a  part  of  the 
air  to  be  warmed  passes  near  the  pan  before  it  is  warmed, 
and  hence  the  amount  of  moisture  taken  up  is  more  or 
less  limited;  another  device  to  add  moisture  to  the  air 
of  furnace-heated  houses  consists  in  placing  a  shallow 
pan  at  each  register  opening  so  that  the  incoming  air 
may  take  up  moisture.  This  plan  is  more  efficacious 
than  the  former. 

In  houses  heated  by  steam  it  has  been  suggested  that 
the  hiimidity  of  the  air  may  be  increased  by  allowing  a 
small  amount  of  steam  to  escape  from  each  radiator. 
This  method  is  objectionable  because  of  the  slight 
noise  from  escaping  steam ;  the  possibility  of  some  of  the 
condensed  steam  dropping  to  the  floor,  and  the  difficulty 
of  supplying  an  appropriate  amount, of  moisture.  In 
large  buildings  equipped  with  appropriate  appliances 
for  heating  the  air  is  propelled  through  the  heating 
plant  by  large  fans,  and  this  gives  an  opportunity  for 
adding  moisture  since  the  air  may  be  forced  through 
screens  over  which  a  fine  stream  of  water  is  falling.  This 
method  is  quite  satisfactory. 

Temperattjee  and  Htjmidity  Conditions  or  Air.^ 

Fahrenheit.  Relative  Humidity. 

Normal 68  degrees.  50  per  cent. 

Cold 50  degrees.  50  per  cent. 

Hot  dry 80  degrees.     20  to  30  per  cent. 

Hot  medium 80  to  86  degrees.  50  per  cent. 

Hot  moist 80  to  86  degrees.  80  per  cent. 

^  Miller  and  Cocks,  Trans.  Amer.  Climatological  Association,  1915. 


CHAPTER  III. 
HEATING. 

Heating  must  always  be  considered  in  connection 
with  ventilation.  This  is  necessary  for  several  reasons. 
The  combustion  of  coal  utilizes  oxygen,  and  as  a  result 
the  products  of  combustion  are  given  off.  In  order  to 
supply  air  for  combustion  and  draught  fresh  air  must  be 
introduced.  It  is  also  necessary  to  have  a  supply  of  fresh 
air  to  replace  the  heated  air  which  escapes  from  the 
building. 

I/OSS  of  Heat  from  Buildings. — Heat  is  required  to 
warm  the  air  of  a  room  to  a  given  temperature,  to  supply 
the  loss  of  the  heat  from  radiation  and  conduction  from 
the  windows  and  walls,  and  to  supply  the  heat  for  the  air 
required  for  ventilation.  The  amount  of  heat  required 
for  these  various  purposes  will  depend  largely  upon  the 
construction  of  the  building,  the  amount  needed  for  pur- 
poses of  ventilation,  and  the  difference  between  the 
inside  and  outside  temperature.  The  loss  of  heat  from 
the  walls  of  buildings  depends  upon  the  material  used, 
its  thickness,  the  number  of  layers,  the  difference  between 
the  temperature  of  outside  and  inside  surfaces,  and  the 
air  exposure.  For  ordinary  temperatures  and  pressures 
about  I  cubic  meter  of  air  will  absorb  i  calorie  in  being 
warmed  i  degree  C,  and  hence  can  be  considered  the 
equivalent  of  i  kilogram  of  water.  The  number  of 
calories  required  for  ventilation  can  then  be  found  by 
multiplying  the  number  of  cubic  meters  of  air  by  the 
difference  between  the  inside  and  outside  temperature, 
and  this  product  by  the  number  of  times  the  air  is 
changed  in  an  hour. 

Degree  of  "Warmth. — The  temperature  most  suitable 

90 


HE  A  T  SUPPLIED  B  Y  RADIA  TTNG  SURF  A  CES.     9 1 

for  healthy  persons  ranges  from  17°  to  20°  C.  for  living 
rooms,  and  15°  to  18°  C.  for  bed-rooms.  For  children 
and  aged  persons  a  somewhat  higher  temperature  is 
required.  No  standard  temperature  can  be  named, 
because  a  temperature  just  comfortable  for  one  person 
may  be  too  warm  or  too  cold  for  others.  Custom  and 
occupation  have  a  great  influence  in  deciding  the  matter. 
Heat  Supplied  by  Radiating  Surfaces. —  The  heat 
used  in  warming  is  obtained  either  by  directly  placing  a 


Fig.  22. — Arrangement  of  indirect  heating  surface. 

heated  surface  in  the  apartment,  in  which  case  the 
warmth  is  said  to  be  obtained  by  direct  heating,  or  else 
by  warming  the  air  used  for  ventilating  purposes  while 
it  is  passing  to  the  room,  in  which  case  the  heating  is 
said  to  be  by  indirect  heating  (Fig.  22). 

Direct  heating  is  performed  by  locating  the  heated  sur- 
face directly  in  the  room,  and  this  surface  may  be  heated 
directly  by  fire,  as  is  the  case  with  stoves  and  fireplaces, 
or  it  may  receive  its  heat  from  steam  or  hot  water 
warmed  in  some  other  portion  of  the  premises  and  con- 
veyed in  pipes.     The  general  principles  of  heating  are 


92 


HEA  TING. 


the  same  in  each  case,  but  in  the  case  of  stoves  the  tem- 
perature is  greatly  in  excess  of  that  derived  from  steam 
or  hot-water  radiators.  The  heat  is  carried  away  from 
the  heated  surface  partly  by  radiation,  in  which  case 
the  heat  passes  in  straight  lines  in  all  directions  and  is 
absorbed  by  the  bodies  of  persons,  by  the  furniture  and 
walls  of  the  room,  without  warming  the  intervening  air 
directly.  The  heat  is  also  carried  away  by  particles  of 
air  coming  in  contact  with  the  heated  surface — that  is, 
by  convection — which  may  be  the  radiating  surface,  the 
bodies  of  persons,  or  the  furniture  and  walls  of  the  room 
which  have  been  warmed  by  the  radiant  heat. 

The  sensations  produced  by  radiant  and  convected  heat 
are  quite  different.  Radiant  heat  has  the  effect  of  in- 
tensely heating  on  the  side  toward  the  source  of  heat, 
and  producing  no  warming  effect  whatever  on  the  oppo- 
site side.  The  heat  which  has  passed  off  by  convection 
is  first  utilized  in  warming  the  air,  and  the  sensation  pro- 
duced is  that  of  heat  equably  distributed.  Radiant  heat 
and  convected  heat  are  essentially  of  the  same  nature  ;  in 
the  one  case  it  is  derived  directly  from  the  source  of  heat, 
and  at  a  high  temperature  ;  in  the  other  case  it  is  received 
from  the  air,  which  is  at  a  comparatively  low  tem- 
perature. 

Resistance  to  Radiation. — The  heat  in  passing  through 
any  metallic  substance  raises  its  temperature  to  an  extent 
which  depends  upon  the  facility  with  which  heat  is  con- 
ducted by  the  body  and  discharged  from- the  other  sur- 
face. It  is  noted  that  heat  meets  with  three  distinct 
classes  of  resistance  in  passing  through  a  metallic  sub- 
stance: First,  that  due  to  the  inner  surface;  second,  that 
due  to  the  thickness  of  the  material ;  and  third,  that  due 
to  the  outer  surface.  The  first  and  third  resistances  are 
due  to  change  in  media,  and,  when  the  material  under 
consideration  is  a  good  conductor,  constitute  the  principal 
portion  of  the  resistance  to  the  passage  of  the  heat. 

Heat  Emitted  by  Radiation. — Heat  emitted  by  radiation, 
per  unit  of  surface  and  unit  of  time,  is  independent  of 


5  VS  TEMS  OF  HE  A  TING.  93 

the  form  and  extent  of  the  heated  body,  provided  there 
are  no  re-entrant  surfaces  which  intercept  rays  of  radiant 
heat.  The  amount  of  heat  projected  from  a  surface  of 
such  form  as  to  radiate  heat  equally  in  all  directions  de- 
pends only  on  the  nature  of  the  surface,  the  excess  of  its 
temperature  over  that  of  the  surrounding  air,  and  the 
absolute  value  of  its  temperature.  The  rate  of  cooling- 
due  to  radiation  is  the  same  for  all  bodies,  but  its  absolute 
value  varies  with  the  nature  of  the  surface.  The  con- 
struction of  the  ordinary  form  of  radiator  is  such  as  to 
present  very  little  free  radiating  surface,  as  all  the  heat 
which  radiates  from  one  tube  to  another  is  reflected  or 
reabsorbed,  and  is  consequently  not  used  in  heating  the 
apartment.  The  greater  portion  of  the  heat  removed  is,  no 
doubt,  absorbed  by  the  air  which  comes  in  contact  with 
the  surface,  or  by  convection.  The  heat  removed  by 
convection  is  independent  of  the  nature  of  the  surface  of 
the  heated  body  and  the  surrounding  absolute  tempera- 
ture. It  depends  on  the  velocity  of  the  moving  air,  and 
is  thought  to  vary  with  the  square  root  of  the  velocity. 
It  also  depends  on  the  form  and  dimensions  of  the  heated 
body,  and  on  the  excess  of  its  temperature  over  that  of 
the  surrounding  air. 

Systems  of  Heating. — There  are  three  systems  of 
heating  in  common  use: 

(i)  Direct.,  where  the  heating  surface  is  in  the  room,  as 
a  stove,  steam  coil,  or  open  fireplace.  The  heat  rays 
from  an  open  fireplace  are  radiant.  They  do  not  warm 
the  air  directly.  Heat  from  a  moderately  hot  stove  or 
from  a  steam  coil  is  very  little  radiant.  The  particles  of 
air  are  heated  and  brought  into  circulation — heating  by 
convection.  This  is  the  cheapest,  though  probably  the 
least  satisfactory,  method  of  heating. 

(2)  Indirect.,  where  the  heating  surface  is  not  in  the 
room  heated,  but  in  some  other  portion  of  the  premises, 
such  as  a  furnace  in  the  cellar.  It  is  impossible  to  heat 
by  the  indirect  method  without  bringing  more  or  less  air 
into  the  room.     It  necessitates  some  ventilation.     It  is 


94  HE  A  TING. 

always  more  costly  than  the  direct  method,  but  is  usually 
more  satisfactory  and  less  troublesome. 

(3)  DirecUindirect^  where  the  heating  surface  is  in  the 
room,  but  has  air  coming  from  the  outside  at  the  same 
time  (usually  so  arranged  that  the  supply  of  outside  air 
can  be  cut  off,  converting  it  into  direct  heating).  Direct- 
indirect  heating  is,  theoretically,  a  desirable  method 
of  heating  and  ventilation  because  it  permits  the  intro- 
duction of  large  quantities  of  fresh  air.  The  method 
is  objectionable  for  two  reasons — it  is  responsible  for 
the  introduction  of  considerable  quantities  of  dust,  and  it 
is  expensive  because  of  the  large  amounts  of  air  that  are 
brought  in  through  the  radiator. 

Direct  Heating". — Open  Fireplaces. — ^With  open  fire- 
places the  heating  is  almost  entirely  by  radiation,  as  there 
is  very  little  opportunity  for  convection  of  heat.  Its  ad- 
vantages are  limited,  though  important.  It  adds  little  of 
the  impurities  of  combustion  to  the  air  of  a  room,  and  it 
ensures  the  extraction  of  considerable  amounts  of  the 
room  air.  The  objections  to  this  mode  of  heating  are 
that  a  very  large  proportion  of  the  heat  is  lost,  and  the 
portion  utilized  is  only  given  off  as  radiant  heat,  thus 
warming  only  one  side  of  the  body,  while  the  opposite 
side  remains  cold.  It  is  also  productive  of  cold  draughts, 
because  the  cold  outside  air  always  tends  to  flow  directly 
toward  the  fireplace.  The  heating  is  inconstant  on 
account  of  changes  in  the  direction  of  the  wind.  This 
method  of  heating  is  of  greatest  importance  as  an  adjunct 
to  other  systems,  such  as  the  heating  of  the  wards  of  a 
hospital  where  an  open  fireplace  is  quite  cheerful,  when 
the  system  of  heating  is  by  means  of  hot  air  or  by  steam. 

Stoves The  principal  advantages  of  stoves  are  that  a 

considerable  amount  of  the  heat  generated  is  utilized,  and 
the  heating  is  under  more  direct  control  and  supervision. 
The  disadvantages  of  this  method  of  heating  are  that 
there  is  a  tendency  for  the  air  to  become  dry,  and  there 
is  no  ready  means  for  introducing  fresh  air.  It  is  objec- 
tionable because  of  the  large  amount  of  dust  which  is. 
produced. 


DIRECT  HE  A  TING.  95 

5team  and  Hot=water  Radiators. — The  use  of  steam 
and  hot-water  radiators  involves  the  installation  of  a  gen- 
eral heating  system  of  which  the  radiators  are  only  a 
small  part.  As  far  as  efficiency  of  heating  is  concerned, 
there  is  very  little  to  choose  between  these  two  methods. 
The  hot-water  system  is  more  expensive  to  install,  but 
the  running  expenses  are  lower  than  for  steam,  because 
it  is  less  expensive  to  warm  the  water  to  ioo°  C.  than  to 
convert  it  into  steam  at  ioo°  C.  Moreover,  in  hot- water 
heating  the  water  is  never  heated  to  the  boiling-point, 
hence  much  less  fuel  is  required. 

Heating  by  5team. — When  water  is  converted  into 
steam  537  calories  are  absorbed  or  rendered  latent  ;  i 
kilogram  of  water  at  100°  C.  requires  as  much  heat  to 
convert  it  into  steam  at  100°  C.  as  would  raise  537  kilo- 
grams I  degree  C,  or  i  kilogram  537  degrees  C.  This 
is  termed  the  latent  heat  of  steam,  and  in  condensing 
back  into  water  this  heat  is  given  off  and  can  be  utilized 
for  purposes  of  heating. 

Steam-heating  plants  are  either  high  or  low  pressure. 
High-pressure  systems  are  now  generally  called  expansive 
systems.  They  carry  steam  at  a  pressure  of  over  700 
grams  to  the  square  centimeter,  while  the  low-pressure 
systems  carry  steam  at  less  than  700  grams,  usually  from 
150  to  350  grams  to  the  square  centimeter.  The  low- 
pressure  systems  are  now  principally  used. 

Systems  of  Piping. — There  are  three  systems  of  piping 
in  use  :  (i)  The  two-pipe  system,  which  is  most  com- 
monly employed,  and  can  be  used  for  either  high-  or 
low-pressure  steam.  The  main  return  riser  is  carried 
below  the  water-line  of  the  boiler.  Various  modifica- 
tions of  this  system  are  in  use.  Each  radiator  is  pro- 
vided with  separate  flow  and  return  pipes.  (2)  A  partial- 
circuit  system,  in  which  the  main  flow  pipe  rises  to  the 
highest  part  of  the  basement  by  one  or  more  branches, 
whence  the  distributing  pipes  run  at  a  slight  incline,  and 
finally  connect  with  the  boiler  below  the  water-line.  The 
radiators  are  connected  by  risers  which  carry  both  flow 
and  return    from   and    to   the  distributing   pipes.     The 


96  HE  A  TING. 

pipes  must  be  made  large.  This  s^^stem  is  employed 
quite  extensively  in  private  houses.  (3)  The  complete- 
circuit  system,  often  called  the  one-pipe  system,  in  which 
the  main  pipe  is  led  directly  to  the  highest  part  of  the 
building  ;  thence  distributing  pipes  are  run  to  the  various 
return  risers,  which  in  turn  connect  with  the  radiating 
surface  and  discharge  in  the  main  return.  The  supply 
for  the  radiating  surface  is  all  taken  from  the  return 
risers,  and  in  some  cases  the  entire  downward  circulation 
passes  through  the  radiating  system. 

Exhaust-steam  Heating. —  This  does  not  imply  any 
particular  method  of  running  the  pipes,  but  proper  con- 
nections must  be  made  between  the  exhaust  and  the 
heating  pipes,  and  provision  must  be  made  for  taking 
care  of  the  condensed  water. 

Hot=water  Heating. — On  account  of  its  high  specific 
heat  water  is  able  to  store  heat,  which  it,  on  cooling,  gives 
up.  One  kilogram  of  water  in  cooling  from  100°  C.  to 
20°  C.  gives  up  80  calories,  which  can  heat  8  x  4  =  32 
kilograms  of  air  through  10°  C,  because  the  specific 
heat  of  air  is  only  one-fourth  that  of  water.  Thirty-two 
kilograms  of  air  are  equal  to  24.61  cubic  meters. 

Methods  of  Piping. — A  system  of  hot- water  heating 
should  present  a  perfect  system  of  circulation  from  the 
heater  to  the  radiating  surface,  and  then  back  to  the 
heater.  An  expansion  tank,  on  the  top  floor,  must  be 
provided  to  prevent  excessive  pressure  due  to  the  heating 
and  consequent  expansion  of  the  water.  In  the  system 
ordinarily  employed  for  hot-water  heating  the  mains  and 
distributing  pipes  have  an  inclination  upward  from  the 
heater,  while  the  returns  are  parallel  to  the  main  and 
have  an  inclination  downward  toward  the  heater,  con- 
necting at  its  lowest  part.  In  this  system  great  care 
must  be  taken  to  produce  nearly  equal  resistance  to  flow 
in  all  the  branches  leading  to  the  difierent  radiators.  It 
will  be  found  that  invariably  the  principal  current  of 
heated  water  will  be  in  the  path  of  least  resistance,  and 
that  a  small  obstruction,  as  any  irregularity  in  the  piping, 


INDIRECT  HE  A  TING.  97 

is  sufficient  to  make  very  great  differences  in  the  amount 
of  heat  received  in  different  parts  of  the  same  system. 

The  expansion  tank  must  in  every  case  be  connected 
to  a  line  of  piping  which  cannot  by  any  possibility  be 
shut  off  from  the  boiler.  It  does  not  seem  to  matter 
whether  it  is  connected  with  the  main  flow  or  with  the 
return. 

Combination  Systems  of  Heating. — Several  methods 
have  been  devised  for  using  the  same  system  of  piping 
alternately  for  steam  or  hot  water,  as  the  demand  for 
higher  or  lower  temperature  might  change. 

Indirect  Heating. — By  Means  of  Steam  Radiators 

Radiators  which  are  placed  in  a  passage  or  flue  which 
supplies  air  to  a  room  supply  heat  by  the  indirect  method. 
These  heaters  are  made  in  various  forms.  They  should  be 
placed  in  a  chamber  or  box  as  nearly  as  possible  at  the 
foot  of  a  vertical  flue  leading  to  the  room  to  be  heated. 
Air  is  admitted  through  a  passage  from  the  outside  pro- 
vided with  suitable  dampers.  The  chamber  surrounding 
the  radiator  and  the  flue  leading  from  the  chamber  are 
constructed  of  masonry  or  of  galvanized  iron,  and  that 
supplying  the  cold  air  of  wood  lined  with  tin.  There 
should  be  a  door  into  the  chamber,  so  that  the  heater 
may  be  cleaned  when  necessary.  It  is  of  great  advantage 
to  have  a  by-pass  and  mixing  dampers  in  the  flues,  so 
that  the  heated  air  can  be  mixed  with  cold  air  in  order  to 
attain  the  desired  temperature  of  the  incoming  air.  These 
dampers  are  often  regulated  automatically  by  means  of 
thermoregulators,  whereby  the  desired  temperature  is 
maintained  by  mixing  requisite  amounts  of  heated  and 
cold  air. 

The  system  of  indirect  heating  by  means  of  steam 
radiators  in  stacks  is  now  very  generally  in  use  for  large 
buildings,  and  when  a  fan  is  used  to  propel  the  air 
through  the  building  affords  the  most  satisfactory  system 
of  ventilation  and  heating.  When  all  the  arrangements 
have  been  properly  made  the  requisite  amount  of  air  can 
be  forced  into  the  building  and  at  the  desired  temperature. 
In  comparison  with  the  efficiency  of  the  ventilation  and 


98  HE  A  TING. 

heating  with  this  system  the  cost  of  the  system  is  no 
great  objection. 

Heating  with  Hot  Air. — The  general  laws  which  apply 
to  hot-air  heating  have  already  been  considered  in  con- 
nection with  ventilation  and  the  indirect  methods  of 
heating.  The  outside  air  is  conducted  through  an 
outer  casing  surrounding  a  furnace,  and  when  heated 
rises  through  the  flues  and  passes  into  the  rooms  above. 
The  rapidity  of  the  circulation  depends  entirely  upon 
the  heat  .of  the  furnace  and  the  height  of  the  flue 
through  which  it  passes.  In  order  that  the  circula- 
tion of  air  through  the  rooms  may  be  more  perfect, 
outlet  openings  must  be  provided  for  the  escape  of  the 
impure  air.  This  system  is  not  adapted  for  large  build- 
ings, because  the  horizontal  distance  to  which  heated  air 
will  travel  is  somewhat  limited.  When  properly  propor- 
tioned, in  buildings  of  moderate  size,  this  system  gives 
fairly  satisfactory  results. 

In  order  that  the  hot-air  system  may  be  satisfactory  in 
every  respect,  the  furnace  should  be  sufficiently  large, 
and  the  ratio  of  heating  surface  to  grate  such  that  a 
large  quantity  of  air  may  be  heated  to  a  low  degree, 
rather  than  a  small  quantity  to  a  high  degree  of 
temperature.  The  air-supply  of  the  furnace  is  usually 
derived  from  the  outside  through  a  shaft  specially  con- 
structed for  this  purpose,  though  in  many  private  dwell- 
ings the  air  is  drawn  immediately  from  the  basement. 
The  disagreeable  effects  of  the  air  of  furnace-heated 
rooms  are  due  to  the  dryness  of  the  air.  The  principal 
objection  to  furnace-heating  is  the  fact  that  when  the  sup- 
ply of  heat  is  shut  off,  the  supply  of  fresh  air  is  also  excluded. 

Heating  with  Electricity — Electrical  energy  can  be 
transformed  into  heat,  and  as  there  are  certain  advantages 
pertaining  to  its  ready  distribution,  it  is  likely  to  come 
into  more  general  use  for  heating.  One  watt  for  one 
hour,  which  is  the  ordinary  commercial  unit  for  elec- 
tricity, is  equal  to  3.41  calories.  Electricity  is  usually 
sold  on  the  basis  of  1000  watt-hours  (i  kilowatt)  as  a 
unit  of  measurement,   the  watts  being  the  product  ob- 


INDIRECT  HE  A  TING.  99 

tained  by  multiplying  the  amount  of  current  estimated 
in  amperes  by  the  pressure  or  intensity  estimated  in  volts  ; 
on  this  basis  1000  watt-houis  are  equivalent  to  3410 
calories.  The  expense  of  electric  heating  must  in  every 
case  be  very  great,  unless  electricity  can  be  supplied  at 
an  exceedingly  low  price. 

Heating  by  Means  of  Gas — In  many  towns  throughout 
the  natural  gas  region  gas  is  used  for  heating  as  well  as 
for  illuminating  purposes.  In  these  localities  gas  is  the 
cheapest  mode  of  heating.  It  is  employed  in  both  the 
direct  and  indirect  systems  of  heating.  When  suitable 
arrangements  are  made  for  carrying  off  the  products  of 
combustion,  and  there  is  a  proper  supply  of  fresh  air  for 
purposes  of  ventilation,  this  is  a  very  satisfactory  method 
of  heating.  In  cold  weather,  where  the  daily  fluctuations 
in  the  temperature  are  not  very  great,  the  gas  heater  can 
be  lighted  and  adjusted,  and  requires  practically  no  atten- 
tion for  weeks  or  even  months.  It  is  therefore  a  great 
saving  in  time  and  annoyance,  and  there  is  no  coal  to 
shovel  nor  ashes  to  remove. 

Heating  by  Means  of  Petroleum. — Within  recent  years 
petroleum  has  been  brought  into  common  use  for  heating 
purposes.  The  advantages  of  oil  heaters  are  that  they 
are  portable  and  may  be  carried  from  one. room  to  another, 
and  the  amount  of  heat  can  be  readily  controlled.  These 
petroleum  stoves  are  objectionable,  however,  from  the 
fact  that  the  combustion  of  the  petroleum  utilizes  large 
quantities  of  the  oxygen  of  the  air  of  the  room,  giving 
off  corresponding  amounts  of  carbon  dioxid.  Babuke  ^ 
has  found  that  in  a  room  of  12  cubic  meters  capacity, 
during  the  first  hour  the  temperature  was  raised  only  4 
degrees  C. ,  and  rose  but  slowly  afterward.  The  propor- 
tion of  carbon  dioxid  in  the  air  exceeded  i  part  per  1000, 
and  reached  in  the  vicinity  of  the  floor  3-10  parts  per 
1000,  and  in  the  upper  part  of  the  room  6-12  parts  per 
1000,  amounts  which  would  be  detrimental  to  health 
when  inhaled  constantly.  The  amount  of  petroleum 
consumed  was  about  a  liter  in  eight  hours. 

'  Zeitschrift  f.  Hygiene,  Bd.  xxxii.,  S.  33. 


CHAPTER    IV. 
WATER   AND   WATER=SUPPLY. 

Physical  Properties  of  Water. — Pure  water  is  a 
colorless,  odorless,  and  tasteless  liquid,  of  neutral  reac- 
tion, and  is  taken  as  the  type  of  all  liquids,  as  air  is  the 
type  of  all  gases. 

Chemical  Composition. — Pure  water  consists  of  2 
parts  by  weight  of  hydrogen  and  16  parts  by  weight  of 
oxygen,  having  a  molecular  weight  of  18.  Two  volumes 
of  hydrogen  combine  with  i  volume  of  oxygen  to  form 
2  volumes  of  water  gas,  having  a  density  of  9.  The 
chemical  formula  for  water  "is  HgO.  The  percentage 
composition  of  water  is  hydrogen,  11. 11;  oxygen,  88.89. 

Chemically  pure  water  does  not  exist  in  nature,  but  is 
made  in  the  laboratory  by  mixmg  the  required  amounts 
of  hydrogen  and  oxygen  gas  and  then  passing  an  electric 
current  through  the  mixture.  The  gases  unite  and  form 
water.  From  the  hygienic  standpoint,  water  as  found  in 
nature  is  either  ' '  pure  "  or  "  impure. ' '  Hygienically  pure 
water  is  one  which  does  not  contain  any  foreign  matter 
which  is  injurious  to  health.  Impure  water  is  one  that 
is  unfit  for  domestic  use.  Water  as  it  exists  in  nature 
contains  a  great  variety  of  substances  derived  from  the 
air  through  which  it  has  fallen  as  rain  or  snow,  and  from 
the  soil  over  and  through  which  it  has  passed.  The 
nature  and  quantity  of  the  mineral  salts  dissolved  out  of 
the  soil  by  water  are  dependent  upon  the  chemical  com- 
position of  the  soil.  The  nature  and  amount  of  organic 
matter  contained  in  the  water  are  dependent  largely  upon 
the  nature  of  the  soil-covering  over  which  the  water  has 

passed. 

100 


SPRING-WATER.  loi 

Water  as  it  occurs  in  nature  may  be  divided  into  rain- 
water, spring-,  ground-,  river-,  lake-,  and  sea-water. 
Each  of  these  natural  waters  varies  somewhat  according 
to  the  locality  from  which  it  is  derived,  though  in  a  gen- 
eral way  all  of  these  natural  waters  possess  character- 
istics which  are  common  to  all  the  waters  of  that  par- 
ticular class. 

Rain-water. — If  raiu-water  were  collected  in  a  chemi- 
cally clean  vessel  at  the  moment  wheu  it  was  condensed, 
it  would  presumably  be  chemically  pure,  but  in  falling 
through  the  atmosphere  it  takes  up  some  of  the  impuri- 
ties in  the  air.  Rain-water  is  one  of  the  purest  of  the 
natural  waters,  but  it  varies  in  purity  with  the  nature  of 
the  atmosphere  through  which  it  has  fallen.  It  is  always 
purer  at  the  end  than  at  the  beginning  of  a  shower.  It 
contains  dissolved  gases  derived  from  the  atmosphere — 
on  an  average  25  cubic  centimeters  per  liter,  of  which 
about  64  per  cent,  is  nitrogen,  34  per  cent,  oxygen,  and 
2  per  cent,  carbon  dioxid.  The  relatively  large  amount 
of  carbon  dioxid,  in  comparison  with  the  proportion  con- 
tained in  atmospheric  air,  is  due  to  its  large  absorption 
coefficient.  Ammonia  is  also  commonly  present.  The 
average  amount  of  solid  matter  in  rain-water  is  39. 5  parts 
per  1,000,000.  Sodium  chlorid  is  the  most  abundant 
salt,  while  nitric  acid  and  nitrates,  sulphuric  acid  and 
sulphates,  and  a  little  organic  matter  are  also  commonly 
present. 

Spring- water. — That  portion  of  the  rain-water  which 
penetrates  the  ground  exercises  a  powerful  chemical 
action  on  the  substances  present  in  the  soil  and  under- 
lying rocks.  This  action  consists  of  solution,  hydration, 
oxidation,  etc.  Rain-water  is  an  oxidizing  agent  on 
account  of  the  considerable  proportion  of  dissolved  oxy- 
gen that  it  contains. 

Springs  may  be  divided  into  two  classes:  Common 
springs,  yielding  fresh,  potable  water;  and  mineral 
springs,  yielding  mineral,  thermal,  or  medicinal  waters, 
in  which  the  dissolved  mineral  matters  render  them  unfit 


I02  WATER  AND   WATER-SUPPLY. 

for  ordinary  domestic  use,    though  of  great  value   for 
tlierapeutic  purposes. 

Ordinary  spring- water  usually  contains  the  gases  of  the 
atmosphere  in  solution.  It  also  contains  various  mineral 
salts  in  solution,  such  as  calcium  carbonate  and  sulphate, 
magnesium  carbonate  and  chlorid,  sodium  chlorid,  alka- 
line sulphates  and  nitrates,  and  silicates.  The  amount 
of  organic  matter  is  usually  small,  and  the  content  in 
free  and  albuminoid  ammonia  is  low.  The  temperature 
of  spring-water  is  usually  lower  than  that  of  the  surround- 
ing air. 

Ground=water  is  the  water  which  has  fallen  upon  the 
siu-face  as  rain  or  snow  and  penetrated  to  varying  depths 
of  the  earth's  crust,  and  can  be  brought  to  the  surface  by 
deep  borings  or  by  the  construction  of  collecting  galleries 
at  points  where  the  water  is  carried  along  underground 
over  impervious  strata.  The  character  of  ground- water 
varies  markedly  in  different  localities  and  at  different 
depths  owing  to  the  geologic  strata  through  and  over 
which  it  has  passed.  In  many  localities  excellent  drink- 
ing-water can  be  obtained,  though  the  quantity  may 
be  somewhat  limited,  depending  upon  circumstances. 

"Well-"water,  if  derived  from  a  deep  well,  is  similar  in 
character  to  spring- water;  but  if  derived  from  a  shallow 
well  it  is  contaminated  with  surface  washings.  Spring- 
water  is  usually  soft,  while  some  well-waters  are  moder- 
ately hard  because  of  the  presence  of  calcium  and  mag- 
nesium salts  in  the  rocks  of  the  locality.  Spring-  and 
well-waters  are  usually  not  rich  in  bacteria  unless 
specially  polluted. 

River-water. — The  course  of  a  great  river  may  be 
divided  into  three  portions — the  mountain  track,  the 
valley  track,  and  the  plain  track;  and  the  composition 
of  the  water  varies  considerably  in  these  three  portions 
of  its  course.  In  the  first  part  it  is  comparatively  pure 
and  partakes  of  the  nature  of  spring- water;  in  the  second 
and  third  parts  it  is  usually  more  or  less  polluted,  depend- 
ing upon  the  density  of  the  population  along  its  course. 
The  composition  of   river-water  is  complex,   as  in  the 


IMPURITIES  IN  WA  TER.  1 03 

case  of  spring-water,  as  the  water  of  rivers  is  largely  de- 
rived from  springs.  The  proportion  of  organic  matter 
and  of  free  and  albnminoid  ammonia  is  usually  higher 
than  in  spring-water;  and  if  polluted  with  sewage  the 
proportion  of  chlorin  is  also  considerably  higher.  The 
character  of  the  water  varies  greatly  with  the  amount  of 
rainfall  and  with  the  nature  of  the  soil-covering  of  the 
valley  and  plain  tracks.  River-water  is  usually  rich 
in  bacteria,  the  number  and  variety  of  species  varying 
greatly  with  the  season  of  the  year  and  the  amount  of 
sewage  pollution, 

I^ake-water. — Lake-water  is  of  variable  composition, 
the  water  of  salt  lakes  being  loaded  with  mineral  con- 
stituents, while  that  of  fresh  lakes  is  usually  of  great 
purity.  Fresh-water  lakes  act  as  settling  basins  for  the 
inflowing  water.  The  sudden  diminution  in  the  velocity 
of  the  current  causes  the  subsidence  of  suspended  mat- 
ters, while  oxidation  of  organic  matters  takes  place  from 
exposure  of  so  large  a  surface  to  the  atmosphere,  and 
from  the  action  of  microscopic  plants  and  bacteria. 

Sea-water. — Sea-water  is  appreciably  alkaline  from 
the  presence  of  carbonates.  The  proportion  of  solids  in 
solution  is  about  3.5  per  cent.;  chlorin  being  the  chief 
constituent,  while  sodium,  calcium,  and  magnesium  are 
next  in  amounts.  It  also  contains  considerable  amounts 
of  atmospheric  gases,  even  at  great  depths,  the  average 
amount  being  from  2  to  3  per  cent,  by  volume. 

Impurities  in  Water. — By  the  term  impurities  is 
meant  such  substances  as  are  directly  injurious  to  health, 
or  that  from  their  association  are  indicative  of  pollution 
though  in  themselves  they  may  be  harmless.  The  im- 
purities in  water  may  be  either  in  suspension  or  solution, 
and  they  may  be  either  gaseous  or  solid,  organic  or  in- 
organic. 

Many  of  the  inorganic  constituents  of  water  are  inju- 
rious only  when  present  in  considerable  amounts — as, 
for  instance,  the  salts  of  calcium  and  magnesium.  These, 
when  present    in  large  amounts,  render  the  water  hard 


I04  WATER  AND  WATER-SUPPLY. 

and  therefore  unsuited  for  domestic  use,  aside  from  the 
fact  that  they  are  productive  of  disordered  function  of 
the  gastro-intestinal  apparatus.  Under  certain  con- 
ditions the  salts  of  magnesium  are  also  believed  to  pro- 
duce goiter.  The  amount  of  sodium  chlorid  commonly 
found  in  natural  waters  is  not  objectionable,  because  it  is 
much  smaller  than  the  amounts  constantly  used  in  season- 
ing food.  Sodium  chlorid  is,  however,  a  most  important 
indication  of  the  pollution  of  surface-waters  with  sewage, 
since  sewage  is  rich  in  chlorin  derived  from  urine.  In 
determining  the  significance  of  the  amount  of  chlorin 
found  in  any  water,  it  is  necessary  to  know  the  normal 
chlorin  content  of  the  surface-waters  of  the  locality,  since 
the  amount  of  chlorin  normally  present  in  surface-waters 
varies  greatly.  The  amount  is  influenced  by  the  prox- 
imity to  the  ocean  or  other  bodies  of  saline  water,  by  the 
proximit}^  to  natural  deposits  of  salt,  and  by  the  geologic 
formation  of  the  locality.  The  chlorin  content  of  sur- 
face-waters of  the  natural  gas  and  oil  regions  is  especially 
high,  and  this  fact  must  be  borne  in  mind  in  determining 
the  significance  of  chlorin  present  in  water  from  such  a 
locality.  The  amount  of  nitrates  and  nitrites  commonly 
found  in  surface-waters  is  without  influence  upon  health. 
These  substances  are,  however,  of  great  interest  and  im- 
portance as  indications  of  the  length  of  time  that  has 
elapsed  since  the  water  has  been  polluted  and  the  extent 
of  the  pollution. 

The  organic  impurities  in  water  are  of  two  kinds,  dead 
organic  matter  of  vegetable  and  animal  origin,  and 
livinof  organisms.  The  amount  of  dead  organic  matter 
commonly  found  in  surface-waters  is  without  efiect  upon 
health.  It  serves,  however,  as  a  most  important  indi- 
cator of  the  extent  and  character  of  pollution.  The 
organic  matter  present  in  water  is  usually  divided  into 
the  nitrogenous  organic  matter  and  the  oxidizable  organic 
matter.  The  nitrogenous  organic  matter  usually  repre- 
sents animal  organic  matter,  and  is  estimated  in  the 
form  of  free  and  albuminoid  ammonia,  though  it  is  not 


IMPURITIES  IN  WA  TER.  105 

always  of  animal  origin,  as  certain  vegetable  compounds 
also  yield  ammonia  on  distillation,  and,  therefore,  are 
nitrogenous  in  character.  The  oxidizable  organic  matter 
is  usually  of  vegetable  origin,  and  is  determined  by  its 
bleaching  effect  upon  a  solution  of  potassium  permanga- 
nate. Neither  the  nitrogenous  organic  matter  nor  the 
oxidizable  organic  matter  is,  as  a  rule,  directly  injurious 
to  health,  and  these  also  are  of  importance  principally  as 
indicators  of  the  nature  and  extent  of  pollution. 

In  making  the  estimates  of  the  amounts  of  these 
various  organic  and  inorganic  impurities  in  water  it  is 
necessary  to  bear  in  mind  that  all  waters  contain  certain 
amounts  of  these  substances.  It  is  only  when  the  quanti- 
ties of  these  substances  found  exceed  to  an  appreciable 
extent  the  normal  content  of  the  surface-waters  of  the 
locality  that  they  become  indicators  of  pollution. 

The  living  organisms  found  in  w^ater  may  be  either 
of  vegetable  or  animal  origin.  The  vegetable  organisms 
found  in  polluted  water  are  of  two  kinds,  the  pathogenic 
and  putrefactive  bacteria,  and  those  organisms  which  are 
of  a  somewhat  higher  organization — certain  chlorophyl- 
bearing  organisms. 

The  bacteria  found  in  polluted  water  which  are  of  the 
greatest  importance  are  the  various  pathogenic  organisms, 
the  most  important  of  which  are  the  typhoid  bacillus,  the 
cholera  organism,  and  Bacillus  sporogenes  of  Klein.  Bacil- 
lus coli  is  also  of  importance,  because  it  is  normally  pres- 
ent in  the  intestinal  discharges  of  man  and  the  domestic 
animals.  But  its  discovery  in  any  surface-water  is  not 
positive  indication  of  sewage  pollution,  as  it  may  have 
gained  entrance  from  street-washings  or  from  the  fecal 
matter  of  any  of  the  domestic  animals.  Its  presence  in 
water  is  cause,  however,  for  suspicion,  because  it  shows 
that  the  water  is  not  properly  protection  against  pollution. 

The  presence  of  Bacillus  sporogenes  is  believed  by 
Klein  to  indicate  sewage  pollution  to  an  equal  extent 
with  the  presence  of  the  colon  bacillus.  It  is  regarded 
as  a  frequent  factor  in  the  production  of  diarrheal  dis- 


io6  WATER  AND   WATER-SUPPLY. 

eases,  especially  in  infants.  There  are  also  a  number  of 
common  putrefactive  bacteria  which  are  not  normally- 
present  in  pure  surface-waters,  and  the  presence  of  which 
is,  to  some  extent  at  least,  indicative  of  pollution.  This 
is  believed  to  be  true  of  such  organisms  as  those  of  the 
proteus  group  and  the  lactic-acid  gt'oup^  and  the  organ- 
isms may  be  instrumental  in  producing  gastro-intestinal 
disturbances  when  present  in  water  in  large  numbers. 
The  various  pyogenic  cocci  may  also  occasionally  be  found 
in  polluted  waters,  and  their  presence  in  drinking-waters 
is  objectionable.  A  streptococcus  has  been  discovered  in 
polluted  waters  by  Houston  and  is  known  as  the  sewage 
streptococcus  of  Houston.  This  organism  is  believed  by 
many  investigators  to  indicate  sewage  contamination  just 
as  positively  as  does  the  presence  of  the  colon  bacillus. 

Bacteria  are  present  to  a  greater  or  less  extent  in  all 
natural  waters.  Many  species  have  their  normal  habitat 
in  water  and  in  the  soil,  through  which  they  gain  en- 
trance to  surface-waters.  The  point  of  hygienic  impor- 
tance is,  therefore,  not  whether  bacteria  are  present  or 
absent,  because  they  are  practically  never  absent;  not 
whether  they  are  few  or  many  in  number,  because  no 
direct  relation  has  been  proved  to  exist  between  their 
number  and  the  purity  or  impurity  of  the  water,  though, 
as  a  rule,  the  larger  the  number  present  the  greater  the 
amount  of  food-supply  for  bacteria  in  such  water,  and 
hence  the  better  facility  for  growth  and  development  of 
all  species  ;  nor  even  how  many  different  species  are 
present.  The  point  of  real  hygienic  importance  is  to 
determine  whether  the  water  does  or  does  not  contain 
any  of  the  organisms  of  specific  diseases.  Since  the 
detection  of  the  typhoid  bacillus  in  suspected  waters,  by 
the  methods  known  at  the  present  time,  is  tedious  and 
difficult,  the  bacteriologist  is  often  obliged  to  base  his 
opinion  as  to  the  purity  of  a  water  upon  the  associated 
species  present,  as  well  as  upon  the  relative  number  of 
bacteria  in  the  water.  It  is  inferred  that  a  water  rich  in 
bacteria  contains  the  necessary  food-supply  for  the  growth 


ODORS  IN  DRINKING-  WA  TER.  107 

and  development  of  bacteria,  and  hence  it  would  support 
the  life  of  any  pathogenic, species  that  might  gain  access 
thereto,  therefore  a  high  bacterial  content  is  looked  upon 
as  indicating  possible  contamination  with  sewage.  If, 
in  addition  to  this,  the  water  contains  well-known  sew- 
age bacteria,  as  Bacillus  coli.  Bacillus  vulgaris.  Bacillus 
sporogenes,  and  the  sewage  streptococcus,  it  is  regarded 
as  being  polluted  with  sewage. 

The  chlorophyl-bearing  organisms  found  in  surface- 
waters  are,  as  a  rule,  harmless,  but  certain  species  when 
present  in  reservoir-water  give  rise  to  disagreeable  odors 
and  taste,  and  hence  are  objectionable.  These  odors  are 
usually  produced  by  the  growth  of  algse,  or  diatoms. 
The  principal  algse  which  have  been  found  to  produce 
these  disao-reeable  odors  in  stored  water  are  different 
varieties  of  volvox,  uroglena,  and  anabena.  The  diatom 
asterionella  has  been  found  to  cause  a  "geranium"  odor 
and  taste  in  stored  water.  Another  pest  of  water-works 
which  has  caused  a  great  deal  of  trouble  in  filling  up  the 
pipes  and  causing  a  brown  sediment  in  the  water  is  the 
so-called  "iron  bacterium,"  or  crenothrix.  It  has  the 
power  of  secreting  iron  in  its  sheath.  Although  it  is  a 
decided  nuisance,  it  is  not  known  to  have  any  harmful 
effect  on  health. 

Odors  in  Drinking-water. — These  fall  into  three 
groups:  (i)  Odors  caused  by  organic  matter  other 
than  living  organisms,  (2)  odors  caused  by  the  de- 
composition of  organic  matter,  (3)  odors  caused  by 
living  organisms. 

The  odors  of  the  first  group  are  usually  characterized 
as  musty,  swampy,  or  peaty  in  character.  Those  due 
to  the  products  of  decomposition  are  similar  to  the  odor 
given  off  by  any  organic  materials  undergoing  decom- 
position. These  odors  when  marked  are  decidedly 
offensive.  The  odors  due  to  living  organisms  are  the 
most  impotent,  since  they  may  occur  in  water  that 
has  been  purified  by  the  most  approved  methods  of 


io8  WA  TER  AND   WA  TER-SUPPL  Y. 

filtration.  For  several  years  for  brief  periods  the 
water  supplied  to  a  portion  of  the  city  of  Philadel- 
phia has  had  a  very  disagreeable  oily  or  fishy  odor 
that  persisted  after  boiling  and  aerating  the  water. 
These  odors  are  believed  to  originate  from  minute 
droplets  of  oil  contained  in  microscopic  water  organ- 
isms, such  as  Diatomacea^,  Cyanophyceae,  Chlorophyceae, 
and  Protozoa. 

The  organisms  producing  the  disagreeable  odors  in 
stored  water  are  unable  to  grow  in  the  absence 
of  sunlight,  and  the  most  satisfactory  method  of 
inhibiting  their  growth  in  stored  waters  is  to  cover 
the  reservoirs  so  as  to  exclude  light.  So  far  as 
known  the  odoriferous  substances  are  not  harmful, 
but  they  are  decidedly  objectionable,  as  most  persons 
suffer  from  thirst  rather  than  drink  water  containing 
them. 

The  more  important  animal  organisms  disseminated 
through  water  are  the  eggs  and  larvae  of  certain  animal 
parasites,  as  the  eggs  of  the  round  worm,  the  eggs  of 
Ankylostoma  duodenal e  and  Rhabdonema  intestinale, 
and  the  larvae  of  the  Guinea-worm,  all  of  which  gain  ac- 
cess through  fecal  matter.  Amebic  dysentery  is  another 
disease  which  it  is  believed  may  be  carried  in  water. 

The  gaseous  impurities  in  water  are  few  in  number 
and  of  somewhat  doubtful  importance.  They  are  hydro- 
gen sulphid,  sulphur  dioxid,  and  the  gaseous  emanations 
arising  from  putrefaction,  as  ammonia,  carbon  dioxid, 
hydrogen  sulphid,  and  marsh  gas.  These  gases  are' 
usually  found  in  water  that  is  charged  with  the  gaseous 
emanations  from  sewers. 

The  solid  impurities  are  principally  mineral  particles, 
such  as  sand,  clay,  and  fine  particles  of  mica.  These 
arise  from  the  soil  over  or  through  which  the  water 
passes,  and  are  most  plentiful  at  the  time  of  freshets. 

Bflfects  of  Impurities  in  Water. — Gaseous  Impuri- 
ties.— Hydrogen    sulphid   and    the   gaseous   emanations 


DISSOL  VED  IMPURITIES.  109 

from  sewers  appear  to  produce  diarrhea.  Sulphur  dioxid, 
when  present  in  considerable  quantities,  produces  disease 
of  the  bones  in  cattle. 

Solid  Particles. — Any  water  that  is  markedly  turbid, 
even  though  the  suspended  matter  be  without  disease- 
producing  qualities  in  itself,  may  cause  diarrhea.  This 
is  the  case  with  the  muddy  waters  of  the  Ganges,  the 
Mississippi  and  other  rivers,  especially  at  certain  seasons 
of  the  year ;  the  turbidity  being  due  to  clayey  particles 
along  with  vegetable  matter.  Finely  divided  mica 
scales  are  said  to  cause  the  "hill  diarrheas"  of  certain 
districts  of  India.  Suspended  animal  matters  (especially 
fecal)  cause  diarrhea  and  dysentery,  and  there  is  little 
doubt  that  such  water  predisposes  to  typhoid  fever  or 
cholera  in  some  degree,  by  producing  an  irritated  cou 
dition  of  the  alimentary  tract. 

Dissolved  Impurities. — Inorganic  Impurities. — Tht 
inorganic  impurities  dissolved  in  water  may  be  divided 
into  three  classes :  The  actively  poisonous  minerals  some- 
times found  in  water,  as  lead,  zinc,  and  arsenic ;  the  al- 
kaline and  earthy  salts,  and  iron,  derived  from  the  soil ; 
and  those  salts  which,  though  not  in  themselves  injurious 
to  health,  are  indicative  of  the  nature  and  extent  of  the 
pollution  of  the  water. 

The  contamination  of  drinking-water  by  the  poisonous 
metals  is  rare  except  in  the  case  of  lead.  The  solvent 
action  of  water  on  lead  pipes  is  dependent  upon  a  variety 
of  conditions.  The  temperature  of  the  water  is  an 
important  factor.  Hot  water  dissolves  lead  much  more 
readily  than  cold  water.  The  character  of  the  water  is 
also  an  important  factor.  Soft  waters,  as  a  rule,  are 
better  solvents  than  hard  waters.  The  presence  of  con- 
siderable amounts  of  dissolved  oxygen  in  water  some- 
times acts  as  a  solvent.  Certain  organic  acids  in  water 
are  also  believed  to  act  as  solvents.  Certain  forms  of 
micro-organisms  seem  to  favor  the  solvent  action.  The 
amount  of  lead  which  will  produce  symptoms  of  poison- 
ing is  variously  stated  by  different  authors,  ranging  from 


no  WATER  AND  WATER-SUPPLY. 

I  part  in  700,000  to  i  part  in  7,000,000  parts  of  water  ; 
though  it  is  probable  that  any  quantity  over  o.  7  part  per 
1,000,000  should  be  considered  as  dangerous.  A  number 
of  propositions  have  been  made  to  prevent  the  solvent 
action  of  water  on  lead  pipe,  such  as  coating  the  interior 
of  the  pipes  with  tin,  fusible  metal,  or  with  coal-tar 
varnish.  The  safest  method  of  preventing  lead-poison- 
ing is  the  substitution  of  iron  pipes  for  lead  pipes  where- 
ever  possible.  Since  the  solvent  action  is  a  rather  slow 
process,  there  is  very  little  danger  from  the  plumbing  of 
modern  dwellings  unless  water  is  used  which  has  been 
standing  in  the  pipes  for  some  time.  For  this  reason  the 
first  portion  of  the  water  drawn  in  the  morning  should 
always  be  discarded,  as  it  is  the  portion  most  likely  to 
contain  lead. 

The  alkaline  earthy  salts  in  water,  constituting  what 
is  known  as  the  hardness  of  water,  are  believed  to  exer- 
cise some  effect  on  those  constantly  using  hard  waters. 
Such  waters  are  believed  to  be  productive  of  calculus 
and  goiter.  It  is  not  eas}'  to  differentiate  the  effects  of 
the  several  earthy  salts,  though  the  calcium  salts  appear 
to  produce  diarrhea,  while  the  magnesium  salts  appear 
to  be  concerned  in  the  production  of  goiter.  Iron  causes 
dyspepsia  and  constipation,  and  the  sulphid  is  believed 
to  be  productive  of  goiter. 

Organic  Impurities. — Dissolved  vegetable  matters,  if 
derived  from  marshes,  are  considered  harmful.  Any  dis- 
solved organic  matter,  whether  vegetable  or  animal,  if 
present  in  large  amount,  may  produce  diarrhea.  The 
animal  matter  derived  from  graveyards  appears  to  be 
especially  injurious.  It  must  be  borne  in  mind,  however, 
that  the  effects  here  attributed  to  the  organic  impurities 
in  water,  in  the  light  of  our  present  knowledge,  must  be 
attributed  largely  to  the  influence  of  micro-organisms 
simultaneously  present. 

Bacteria. — The  diseases  produced  by  the  presence  of 
specific  pathogenic  bacteria  in  drinking-water  are  typhoid 
fever,  Asiatic  cholera,  dysentery,  and  diarrhea,  the  latter 


DISSOL  VED  IMPURITIES.  1 1 1 

possibly  through  the  presence  of  Bacillus  sporogenes.  In 
addition  to  these  diseases,  diarrhea  and  dysentery  may  be 
produced  through  the  presence  of  certain  other  micro- 
organisms in  drinking-water. 

Typhoid  Fever. — The  belief  that  typhoid  fever  can  be 
communicated  through  drinking-water  is  comparatively 
modern.  Austin  Flint,  in  this  country,  and  Alfred  Car- 
penter, in  England,  about  1852,  having  been  the  first  to 
establish  the  fact.  It  is  now  hardly  questioned  by  any 
one  that  has  studied  the  history  of  different  epidemics. 
Hirsch  considers  that  few  points  in  the  etiology  of 
typhoid  fever  are  so  certainly  proved  as  the  conveyance 
of  the  specific  bacilli  by  drinking-water,  or  by  food  con- 
taminated with  polluted  drinking-water.  Bacillus  ty- 
phosus is  the  actual  cause  of  the  disease,  and  no  water 
can  convey  the  disease  without  containing  the  specific 
organism. 

A  number  of  epidemics  of  typhoid  fever  have  been 
traced  directly  to  polluted  drinking-water.  The  preva- 
lence of  typhoid  fever  in  any  community  should  always 
lead  to  an  investigation  of  the  nature  of  the  water-supply 
and  the  removal  of  sources  of  pollution.  Cities  using 
polluted  river-  or  lake-water  always  have  a  high  death- 
rate  from  typhoid  fever.  Changing  to  a  pure  water- 
supply  or  the  purification  of  the  polluted  water  is  followed 
immediately  by  a  reduction  in  the  mortality  from  typhoid 
fever.  The  reduction  in  the  death-rate  from  typhoid 
fever  at  Lawrence,  Mass.,  at  Philadelphia,  Pa,,  and  other 
places  after  the  introduction  of  filtered  water,  was  most 
marked,  and  has  continued  low  ever  since.  The  reduc- 
tion in  the  death-rate  from  typhoid  fever  in  Newark  and 
Jersey  City,  N.  J.,  after  abandoning  the  polluted  water 
of  the  Passaic  River  for  impounded  surface-water,  was 
also  quite  marked. 

Asiatic  Cholera. — The  question  of  the  spread  of  cholera 
by  water  is,  in  many  respects,  as  well  established  as  the 
spread  of  typhoid  fever.  The  theory  of  the  spread  of 
cholera  throuofh  drinking:- water  dates  back  to  the  writings 


112 


WA  TER  AND   WA  TER-SUPPL  V. 


of  Dr.  Snow  in  1849  ^^^  ^^54-  The  specific  organism 
of  cholera  is  the  "comma  bacillus,"  or  spirillum  dis- 
covered by  Koch  in  1882. 


CHOLERA 


Fig.  23. — The  black  dots  show  the  location  and  number  of  the  cholera  cases 
in  both  Hamburg  (to  the  right  of  the  red  dividing  line)  and  Altona  (to  the 
left  of  that  line)  (Abbott). 

The  relation  of  polluted  water-supplies  to  outbreaks 
of  cholera  is  shown  most  graphically  in  the  accompanying 
chart  (Fig.  23)  indicating  the  experiences  of  the  adjoin- 


DISSOL  VED  IMPURITIES.  1 13 

iug  cities  Hamburg  and  Altona,  in  1892.  Both  cities 
derived  their  water-supply  from  the  river  Elbe.  Ham- 
burg used  the  raw,  unfiltered  water.  The  supply  of 
Altona  was  taken  from  the  river  at  a  point  below  the 
Hamburg  sewer  outfall,  but  subjected  to  sand  filtration. 
The  two  cities  adjoin,  and  are  practically  one  city;  the 
division  between  the  two  for  the  most  part  follows  one 
of  the  streets.  There  were  16,957  cases  and  8606  deaths 
from  cholera  in  Hamburg,  and  only  516  cases  and  316 
deaths  in  Altona  during  the  same  time,  giving  a  death- 
rate  of  1343  per  100,000  of  population  for  unfiltered 
river- water,  and  a  death-rate  of  211  per  100,000  of  popu- 
lation for  filtered  water.  A  number  of  the  cases  occur- 
ring in  Altona  were  traced  directly  to  infection  by  Ham- 
burg water  occurring  in  persons  working  in  Hamburg 
but  living  in  iVltona. 

Diarrhea  and  Dysentery. — Klein  ^  believes  Bacillus 
sporogenes  to  be  the  etiologic  factor  in  many  cases  of 
diarrhea,  and  that  it  probably  gains  entrance  to  drinking- 
water  through  sewage  and  surface  washings  containing 
the  fecal  matter  of  domestic  animals.  Bacillus  dysenteriae 
is  now  generally  regarded  as  most  probably  also  carried 
in  infected  waters.  Besides  these,  certain  putrefactive 
organisms,  such  as  those  of  the  proteus  and  lactic-acid 
groups,  are  also  believed  to  be  concerned  in  the  causation 
of  diarrhea  under  certain  conditions. 

The  discovery  of  Messrs.  Duval  and  Basset  ^  that  ' '  in- 
fantile diarrhea"  is  due  to  Bacillus  dysenteriae  has  stimu- 
lated bacteriologists  to  extended  studies  upon  the  etiolog}- 
and  modes  of  transmission  of  diarrheal  diseases  in  general. 
The  greater  prevalence  of  diarrheal  diseases  in  hand-fed, 
as  compared  with  breast-fed,  infants  points  to  the  food- 
supply  as  the  source  or  carrier  of  the  infectious  agent. 
The  results  of  the  investigations  upon  the  bacterial  con- 
tent of  milk  indicate  that  the  specific  micro-organisms  of 

^  Report  of  the  Medical  Officer  of  the  Local  Government  Board  for  1895-96 
and  1897-98. 

^American  Medicine,  vd.  iv. 


114  WA  TER  AND   WA  TER-SUPPL  V. 

infantile  diarrhea  gain  access  to  the  milk  through  con- 
taminated water  used  in  cleansing  the  milk-containers,  or 
water  added  for  purposes  of  dilution. 

The  systematic  study  of  more  than  fifty  organisms  of 
the  colon  group  isolated  from  polluted  waters  failed  to 
demonstrate  the  presence  of  Bacillus  dysenteriae  in  these 
waters.  Further  investigations  with  improved  methods 
may,  however,  show  the  presence  of  these  organisms  in 
polluted  waters. 

Goiter. — It  has  always  been  a  widespread  belief  that 
goiter  and  cretinism  are  caused  by  the  use  of  drinking- 
water  from  particular  sources,  and  there  is  some  founda- 
tion for  this  belief  These  diseases  appear  to  be  asso- 
ciated, to  some  extent  at  least,  with  certain  geologic  for- 
mations, especially  those  localities  in  which  magnesian 
limestone  is  found.  Various  observers  have,  in  turn, 
considered  the  salts  of  calcium  and  magnesium,  as  well 
as  other  metallic  substances,  especially  iron  sulphate,  or 
copper,  or  deficiency  of  chlorids  or  of  iodin,  to  be  the 
cause.  Hirsch  believes  that  endemic  goiter  should  be 
considered  as  an  infectious  disease  produced  by  a  specific 
poison. 

Cancel^. — Within  recent  years  the  discovery  of  certain 
appearances  in  the  cells  in  cancerous  tumors  has  given 
rise  to  the  belief  that  this  disease  may  be  due  to  an 
organism  derived  from  soil  or  water.  Thus  far  no  satis- 
factory evidence  has  been  brought  forward  to  substantiate 
this  belief 

Approximate  Composition  of  Drinking-water. — 
De  Chaumont  classified  different  waters  into  four  classes, 
with  regard  to  their  degree  of  purity.  This  classifica- 
tion is  serviceable  in  forming  an  opinion  as  to  the  use- 
fulness of  a  water  for  domestic  purposes,  though  it  can- 
not be  followed  strictly  in  every  particular,  because  geo- 
logic conditions  may  influence  the  constitution  of  a  water 
to  such  an  extent  as  to  bring  it  under  the  class  of  sus- 
picious or  impure  waters  with  regard  to  the  mineral  con- 
stituents, without  really  rendering  the  water  suspicious. 


DAIL  V  AMOUNT  OF  DRINKING-  WA  TER.       1 15 

It  is  always  necessary  to  have  some  knowledge  of  the 
geologic  formation  of  the  locality. 

The  table  of  approximate  composition  of  pm-e,  usable, 
suspicious,  and  impure  waters  should  not  be  regarded  as 
absolute  because  variations  may  occur  in  the  waters  of 
certain  localities  which  are  traceable  to  the  peculiar 
geologic  formations  of  the  locality  and  not  to  pollution. 
It  is  highly  necessary  to  have  a  knowledge  of  the  geo- 
logic formations  that  may  have  contributed  some  of 
their  constituents  to  the  water;  otherwise  serviceable 
waters  may  be  condemned. 


Chemical  constituents  stated  in 
parts  per  1,000,000. 

Total  solids 

Chlorin 

N  as  nitrates 

N  as  nitrites 

N  as  free  NH3 

N  as  albuminoid  NHj  . 
Organic  matter 


Pure. 

Usable. 

Less  than 

Less  than 

70.000 

430.000 

14.000 

40.000 

0.140 

1. 1 20 

nil 

ml 

0.020 

0.050 

0.050 

O.IOO 

0.250 

1. 000 

Suspicious. 


430.000  to  7 10.000 

4000010     70.000 

1. 1 20 to    24.000 

0.500 

0.050  to 
O.IOO  to 
1. 000  to 


O.IOO 

0.125 

1.500 


Impure. 


Over 
710.000 
70.000 
2.400 
0.500 
O.IOO 
0.125 
1.500 


Amount  of  Drinking-water  Required  Daily.— For 
Drinking  and  Cooking. — An  adult  requires,  on  an  average, 
3  liters  of  water  daily;  of  this  amount,  i  liter  is  con- 
tained in  the  solid  food  that  is  ingested.  About  2  liters 
should  be  allowed  for  drinking-purposes,  either  as  plain 
water,  or  as  tea,  coffee,  etc. 

For  Ablution. — The  quantity  used  varies  very  much 
according  to  the  cleanliness  of  the  individual.  About  25 
liters  may  be  allowed,  of  which  10  to  15  liters  will  serve 
for  a  sponge  bath.  If  a  general  bath  is  taken,  the  daily 
amount  is  very  much  increased,  and  may  be  stated  at 
from  250  to  300  liters. 

For  Laundry  and  Kitchen  Use. — About  15  liters  may 
serve  for  laundry  purposes,  and  the  same  amount  for 
house  and  utensil  cleansing. 

For  Water=closets. — The  usual  quantity  provided  in 
the   "water-waste-preventer"    cisterns  now  supplied   to 


1 1 6  WA  TER  AND   WA  TER-SUPPL  Y. 

closets  is  lo  to  15  liters.  These  contrivances  effect  a 
great  saving  in  water  and  meet  all  the  requirements. 

For  other  Purposes — The  need  of  water  in  cities  for 
other  than  domestic  purposes,  such  as  manufacturing, 
washing  of  sidewalks,  sprinkling  of  streets  and  lawns,  and 
for  hospitals,  brings  the  daily  supply  up  to  a  very  large 
amount.  The  estimations  of  the  Chief  of  the  Bureau  of 
Water  of  Philadelphia,  of  750  liters  per  head  per  day, 
should  meet  all  legitimate  requirements.  The  supply  of 
890  liters  per  day  shows  that  there  is  an  enormous  waste 
of  water. ^  It  is  believed  that  a  supply  of  500  liters  per 
person  per  day  would  be  a  generous  supply  of  water 
for  all  purposes  in  cities  and  towns.  The  supply  in  many 
European  cities  is  less  than  one-half  as  much.  Most 
American  cities  have  been  extremely  lavish  in  the  supply 
of  water.  Since,  however,  it  has  become  necessary  to 
purify  all  domestic  water  supplies  the  amount  of  water 
supplied  becomes  a  most  important  economic  question. 
Wasting  of  water  should  be  carefully  controlled,  but 
sufficient  amounts  should  be  supplied  for  all  legitimate 
needs. 

Source  of  Water-supplies. — Surface=water — By  sur- 
face-water is  meant  the  water  discharged  from  the  sur- 
face of  a  catchment  area,  as  opposed  to  that  collected 
from  wells  and  galleries.  Strictly  speaking,  the  water 
in  rivers  and  lakes  is  surface-water;  but  as  the  supply 
from  these  sources  is  often  obtained  by  special  works  it 
is  convenient  to  restrict  the  term  surface-water  to  sup- 
plies obtained  by  means  of  impounding  reservoirs.  Such 
surface  supplies  depend  upon  the  rainfall  for  their  ex- 
istence and  upon  the  natural  features  of  the  watershed 
for  their  character. 

It  is  generally  possible  to  secure  statistics  of  the  rain- 
fall in  the  neighborhood  of  most  places  large  enough  to 
have  water-works,  and  from  such  statistics  and  an  in- 

1  See  "Report  of  the  Mayor  of  Philadelphia  on  Extension  and  Improve- 
ment of  the  Water-supply,"  1899. 


SOURCE  OF  WATER-SUPPLIES.  n? 

spection  of  the  catchment  area  the  probable  amount  of 

water  usually  available  may  be  determined.  The  maps 
of  the  State  and  National  geologic  surveys  are  of  much 
value  in  determining  the  sources  from  which  a  supply 
may  be  obtained. 

The  surface  area  that  is  necessary  in  order  to  furnish 
a  supply  sufficient  for  a  large  city  is  enormous.  The 
water-supply  of  a  large  part  of  New  York  City  is  derived 
from  the  Croton  watershed,  and  it  is  frequently  stated 
that  the  amount  of  water  available  is  barely  sufficient  for 
present  purposes,  and  that  preparation  must  be  made  for 
an  extension  without  delay.  In  a  recent  report  to  the 
mayor  of  the  city  the  water-supply  commissioner  as- 
serts: "The  people  and  government  of  the  city  must 
now  and  without  delay  face  the  choice  between  two 
alternatives:  They  must  either  take  prompt  and  decisive 
action  for  the  acquisition  of  large  additions  to  the  water- 
supply  beyond  the  Croton  watersheds,  or  institute  meas- 
ures to  reduce  the  per  capita  consumption  of  water.  The 
average  daily  consumption  of  Croton  water  has  increased 
from  223,000,000  gallons  in  1898  to  253,000,000  gallons 
in  1899.  At  the  same  annual  increase  in  succeeding 
years  the  limit  of  the  capacity  of  the  two  Croton  aque- 
ducts— 380,000,000  gallons  a  day — will  be  reached  and 
exceeded  in  five  years,  a  shorter  time  than  that  in  which 
it  would  be  possible  to  acquire  new  sources  of  supply 
and  to  build  new  reservoirs  and  new  aqueducts." 

The  quality  of  the  water  from  a  watershed  depends 
upon  the  population  of  the  area,  the  number  of  swamps 
in  it,  and  the  nature  of  the  geologic  strata  over  which  it 
flows.  If  the  population  on  the  watershed  exceeds  about 
100  per  square  kilometer,  the  stored  water  is  in  danger 
of  being  polluted,  and  often  proves  troublesome  from  bad 
taste  and  odor.  If  there  are  numerous  swamps  on  the 
watershed,  the  water  is  likely  to  be  dark  in  color,  and 
may  be  objectionable  on  this  account.  If  limestone  is 
common,  the  water  is  liable  to  be  too  hard  for  either 
domestic  use  or  for  manufacturing  purposes. 


Ii8  WATER  AND   WATER-SUPPLY. 

The  suitability  of  the  water  for  a  municipal  supply 
depends  upon  its  freedom  from  sewage  contamination, 
the  degree  of  hardness,  as  well  as  its  color,  odor,  and 
taste.  Its  general  character  may  be  determined  by  an 
inspection  of  the  entire  watershed. 

Supplies  from  Rivers. — The  nature  and  amount  of 
water  available  from  a  river  must  be  determined  by 
systematic  study  of  the  flow  at  both  high-  and  low- 
water  seasons.  The  character  of  the  river-water  will 
depend  upon  the  density  of  the  population  along  its 
entire  length,  the  nature  of  the  surface-covering  of  the 
watershed,  and  the  nature  of  the  geologic  formations. 

In  comparing  the  relative  advantages  of  river-water 
and  of  impounded  surface-water,  it  is  necessary  to  take 
into  account  the  amount  of  water  obtainable  from  either 
source,  the  relative  purity  of  each,  and  the  expense  of 
extending  both  systems  so  as  to  meet  the  demands  of 
the  future.  This  question  had  been  under  discussion  in 
Philadelphia  for  a  long  time,  owing  to  the  degree  of  pol- 
lution of  the  water.  Many  competent  observers  had 
made  more  or  less  exhaustive  studies  of  the  conditions 
involved,  but  with  varying  results  ;  some  favoring  the 
abandonment  of  the  river-water  and  resorting  to  the  use 
of  impounded  water  from  the  headwaters  of  the  tribu- 
taries of  the  Delaware  and  Schuylkill  Rivers,  others 
favoring  the  purification  of  the  supply  in  use  as  being 
the  most  feasible  and  the  less  expensive  procedure.  The 
commission  of  experts  appointed  early  in  1899  to  make 
another  detailed  study  of  the  whole  question  reported  in 
favor  of  filtration  of  the  river- water.  This  plan  has  been 
adopted,  and  the  entire  population  of  the  city  is  now 
(1914)  receiving  river-water  that  has  been  purified  by 
slow  sand  filtration. 

Lake  and  Pond  Supplies. — The  use  of  lakes  and  ponds 
as  sources  of  supplies  is  not  available  for  many  localities. 
Where  such  supplies  are  available  and  they  are  of  un- 
doubted purity,  they  usually  meet  all  the  conditions. 
In  the  use  of  lake-waters  the  disposal  of  sewage,  how- 


SOURCE  OF  WATER-SUPPLIES.  1 19 

ever,  becomes  a  serious  problem,  as  in  Chicago.  Here 
the  sewage  was  disposed  of  by  leading  it  back  into  the 
lake,  with  the  result  of  polluting  the  lake-water  to  such 
an  extent  as  to  render  it  dangerous.  Hven  carrying  the 
fresh-water  intake  far  out  into  the  lake  failed  to  remedy 
the  matter  satisfactorily,  and,  as  a  result,  the  drainage 
canal  leading  to  the  Mississippi  River  was  constructed  to 
dispose  of  the  sewage. 

Qround=water  Supplies. — There  are  two  classes  of 
ground-water,  the  water  which  filters  from  a  river  or 
pond  into  the  soil  forming  its  basin,  and  the  water  which 
has  entered  the  ground  from  a  variety  of  sources,  but  has 
been  checked  in  its  downward  percolation  by  more  or 
less  impervious  strata. 

The  water  of  the  first  class  retains  many  of  the  char- 
acteristics of  the  river-  or  pond-water  from  which  it  is 
derived,  though  the  nature  of  the  soil  through  which  it 
passes  influences  its  character  to  some  extent,  improving 
it  during  its  passage  through  the  soil.  The  water  of  the 
second  class  is  influenced  to  some  extent  by  the  geologic 
formation  of  the  locality  and  the  depth  to  which  it  has 
penetrated.    Generally  it  is  a  water  of  considerable  purity. 

With  regard  to  the  method  of  collecting  ground-water, 
the  general  plans  must  vary  with  the  particular  conditions 
presented  by  the  locality.  These  methods,  in  a  general 
way,  may  be  said  to  be  either  by  means  of  a  large  circu- 
lar well,  of  tubular  wells,  or  of  filtering  and  collecting 
galleries. 

The  amount  of  water  that  may  be  obtained  from  deep 
and  shallow  wells  depends  upon  the  same  conditions  as 
those  influencing  the  amount  of  surface-water.  Besides 
this,  the  quantity  is  also  dependent  upon  the  porosity  of 
the  soil  or  its  capacity  for  storing  water.  No  more  water 
can  be  obtained  from  an  area  drained  by  the  well  than 
that  which  falls  upon  the  surface  in  the  form  of  rain. 
The  amount  of  ground-water  is  therefore  somewhat  lim- 
ited. The  largest  yields  of  ground-water  for  the  supply 
of  cities  in  this  country  have  been  as  follows: 


1 20  WA  TER  AND   WA  TER-SUPPL  V. 

Brooklyn,  N.  Y., 150.000  cubic  meters  per  day. 

Memphis,  Tenn., 75. 000  "  " 

Lowell,  Mass., 56,250 

Dayton,  Ohio, 31,650  "  " 

The  amount  of  water  that  could  be  obtained  from  this 
source  would  be  only  a  small  fractional  part  of  the  daily 
consumption  of  a  large  city.  For  small  towns  this  source 
of  supply  is  available  when  there  is  no  other  that  is 
equally  pure  and  more  accessible. 

Springs — The  relative  purity  of  spring-waters  renders 
these  a  useful  source  of  supply.  For  small  communities 
the  supply  is  often  sufficient  for  ordinary  requirements, 
or  it  may  be  extended  by  combining  the  supply  6f 
neighboring  springs.  The  nature  of  the  location  of 
many  springs  renders  them  but  little  liable  to  pollu- 
tion, and  at  the  same  time  it  frequently  renders  the 
collection  and  utilization  of  the  water  an  easy  matter. 

Artesian  Wells. — In  many  localities  the  only  available 
source  of  supply  is  that  from  artesian  wells.  The  depth 
of  the  wells  is  dependent  upon  the  depth  at  which  water- 
bearing strata  are  to  be  found.  The  nature  of  the  water 
obtained  is  influenced  directly  by  the  chemical  composi- 
tion of  the  strata  through  which  the  water  has  passed. 
As  a  rule  these  waters  are  quite  hard,  though  of  great 
purity.  In  certain  localities,  as  in  North  and  South 
Dakota,  the  waters  are  quite  alkaline  and  contain  mineral 
matter  to  the  extent  of  4000  to  5000  parts  per  1,000,000 
parts  of  water,  or  even  more.  The  healthfulness.  of 
these  waters  is  directly  dependent  upon  the  nature  and 
amount  of  mineral  matter  contained  in  them.  It  is 
evident  that  the  constant  use  of  such  waters  as  those 
found  in  the  Dakotas  would  prove  of  considerable  injury 
to  the  organs  of  elimination,  especially  the  kidneys. 
Experience  has  shown  that  these  waters  cannot  be  used 
constantly  with  impunity.  They  are  usually  used  only 
when  other  available  supplies  fail  from  long-continued 
drought. 


STORAGE  OF  WATER.  121 

Reudiger^  found  that  in  portions  of  North  Dakota 
people  drink  water  that  has  an  alkalinity  of  from  900  to 
1200  parts  per  million,  due  to  the  presence  of  carbonates 
and  bicarbonates.  He  traces  the  injurious  effects  of  these 
waters  with  high  mineral  content  to  the  presence  of  large 
quantities  of  magnesium  and  sodium  sulphate.  He  be- 
lieves that  a  water  should  be  considered  unsuited  for 
drinking  if  it  contains  over  200  parts  per  million  of  mag- 
nesium in  the  form  of  sulphate.  Waters  with  smaller 
quantities  of  magnesium  sulphate  may  be  injurious  if  con- 
siderable quantities  of  sodium  sulphate  are  also  present. 

Storage  of  Water. — Water  is  stored  on  a  large  scale 
in  reservoirs,  and  on  a  small  scale  in  tanks  or  cisterns. 
Reservoirs  are  natural  or  artificial  basins  appropriated  or 
formed  for  the  purpose  of  reserving  or  storing  water. 
They  are  called  storage  reservoirs  when  they  are  intended 
to  retain  the  excess  of  rainfall  during  the  rainy  season  ; 
service  reservoirs  when  they  are  intended  to  hold  the 
supply  for  immediate  distribution.  Cisterns  are  neces- 
sary in  houses  supplied  on  the  intermittent  system,  as  in 
rural  districts.  The  size  of  the  cistern  will  depend  upon 
several  conditions,  as  the  amount  of  supply  required 
according  to  the  number  of  persons  occupying  the  house, 
and  the  frequency  with  which  the  supply  can  be  replen- 
ished. The  materials  used  in  the  construction  of  cis- 
terns are  usually  cement  and  slate.  These  materials 
yield  nothing  to  the  stored  water.  Common  mortar 
should  not  be  used,  because  it  gives  up  lime  to  the  water. 
Neither  should  any  metal  be  employed. 

Purification  of  Water. — The  purification  of  water 
used  for  drinking-purposes  may  be  directed  to  its  physical, 
chemical,  or  biologic  condition.  Water  that  is  turbid 
may  be  rendered  clear;  water  that  has  a  large  amount  of 
dissolved  mineral  impurities  may  be  deprived  of  them, 
at  least  to  some  extent;  water  that  contains  micro-organ- 
isms, pathogenic  or  harmless,  may  be  rendered  almost  or 
quite    free    from     bacteria.       Physical,     chemical,     and 

"^  Am.  Jour,  of  Puhlic  Health,  vol.  iii.,  1912. 


122  WATER  AND   WATER-SUPPLY. 

mechanical  means   are  employed  to   accomplish  these 
ends. 

In  former  times  mechanical  purification  alone  was 
attempted,  and  a  water  that  was  clear  and  sparkling  was 
considered  fit  to  drink,  no  regard  being  had  to  its  chemi- 
cal and  biologic  impurities.  With  the  advance  in  chem- 
ical science  and  application  of  the  knowledge  it  afibrded, 
the  chief  attention  was  directed  to  the  mineral  matters  in 
solution,  especially  those  indicating  fecal  pollution. 
Within  recent  years,  since  the  cause  and  the  mode  of 
dissemination  of  certain  epidemic  diseases  have  been 
traced  to  the  pollution  of  drinking-waters  with  sewage, 
the  position  is  now  taken  that  purification  of  water,  to  be 
efficacious,  must  not  only  render  a  water  clear  and  free 
from  mechanical  and  mineral  impurities,  but  must  also 
deprive  it  of  the  pathogenic  bacteria  contained  therein. 
This  latter  function  is  now  considered  the  most  important 
in  any  process  of  purification. 

Methods  of  Purification. — 5eK=purification  of  Bodies 
of  Water. — The  power  of  self-purification  which  many 
streams  and  lakes  exhibit  is  in  some  instances  quite 
remarkable.  It  was  supposed,  not  long  since,  that  pol- 
luted rivers  would,  in  time,  completely  purify  themselves. 
This  has,  however,  been  refuted  by  recent  investiga- 
tions. The  process  of  self-purification  in  streams  and 
lakes  is  a  composite  one.  The  factors  which  are  con- 
cerned in  this  process  are  the  following  : 

I.  Sedimentation.  The  suspended  particles,  both  or- 
ganic and  inorganic,  sink  to  the  bottom.  2.  Oxidation. 
In  consequence  of  the  movement  of  the  current  the  water 
becomes  aerated,  and  comes  in  contact  with  fresh  portions 
of  oxygen,  and  this  oxidizes  the  organic  matter.  Sun- 
light accelerates  the  oxidation  of  the  organic  matter.  3. 
Precipitation.  During  the  course  of  the  stream  certain 
insoluble  inorganic  compounds  (as  sulphur  compounds) 
may  be  formed  and  precipitated,  or  humus  substances 
may  be  precipitated  through  the  action  of  clay,  aluminum 


ME  THODS  OF  PURIFICA  TION.  1 23 

sulphate,  and  hydroxid.  4.  Dilution.  The  entrance  of 
pure  water  from  the  tributaries  and  from  ground-water 
dilutes  the  water.  5.  Water  plants  of  different  forms  (as 
algae)  and  infusoria  digest  dissolved  and,  at  times,  un- 
dissolved organic  substances.  6.  The  bacteria  convert 
the  organic  matter  into  simple  inorganic  compounds, 
such  as  carbon  dioxid,   ammonia,   and  water. 

Jordan  ^  studied  the  extent  of  the  purifying  power  of 
bacteria  in  the  Illinois  River  and  its  tributaries.  Sam- 
ples were  collected  at  various  points  along  the  Chicago 
drainage  canal  and  the  Desplaines,  Illinois,  and  Missis- 
sippi rivers.  "  In  the  flow  of  twenty-four  miles  between 
Morris  and  Ottawa,  the  river  freed  itself  from  a  great 
mass  of  sewage  bacteria  with  which  it  was  originally 
laden,  and  at  Ottawa  this  was  not  greatly  in  excess  of 
that  found  in  the  flow  of  the  tributary  streams."  He 
attaches  most  importance  to  the  influence  of  sedimenta- 
tion and  to  the  diminution  of  the  food-supply.  Less 
influence  is  believed  to  be  exerted  by  sunlight  and  the 
agencies  of  the  animal  and  vegetable  life  in  the  stream. 
He  believes  that  the  influence  of  the  diminution  of  the 
food-supply  through  the  agencies  of  the  bacteria  them- 
selves is  a  factor  that  has  not  received  due  consideration. 

A  very  good  example  of  the  inadequacy  of  the  self- 
purification  of  streams,  in  distances  of  15  to  30  kilo- 
meters, is  afforded  by  the  Merrimac  River,  in  Massachu- 
setts. Epidemics  of  typhoid  fever  have  followed  one 
another,  occurring  first  in  Lowell,  from  two  to  three 
weeks  later  in  Lawrence,  and  in  one  instance  even  in 
Newburyport.  The  refuse  of  one  city  was  carried 
directly  to  the  next,  and  the  lower  cities,  using  the  river- 
water  for  drinking-purposes,  were  afflicted  with  serious 
epidemics.  The  dilution,  sedimentation,  and  aeration 
were  insufficient  to  remove  the  typhoid  bacilli. 

Filtration — Filtration  is  one  of  the  most  satisfactory 
processes  of  purifying  water.     It  was  formerly  supposed 

^  Jour.  Exper.  Med.,  Dec.  15,  1900. 


1 24  WA  TER  AND   WA  TER-SUPPL  V. 

that  the  process  was  merely  a  mechanical  one  by  which 
the  particles  suspended  in  the  water  were  removed. 
While  this  is  in  part  true,  it  is  now  well  established 
that,  besides  removing  suspended  particles,  the  filtering 
process  through  properly  constructed  beds  of  sand  will 
diminish  the  amount  of  organic  matter  in  the  water, 
while  the  bacteria  are  very  much  reduced  in  number. 
This  process  is  similar  to  the  natural  processes  of  puri- 
fication constantly  going  on  in  the  soil,  and  is  brought 
about  through  the  activity  of  the  same  agents — the  nitri- 
fying bacteria.  All  well-  and  spring-water,  the  so-called 
ground-waters,  have  been  filtered  by  the  natural  process. 

The  object  of  all  filtration  of  water  is  purification. 
This  purification,  wherever  necessary,  should  be  carried 
out  by  the  municipal  authorities.  In  other  words,  a 
water  should  be  furnished  to  the  public  which  requires 
no  purification  at  the  hands  of  the  consumers  them- 
selves. 

Sa7td  Filtratio7t. — Filtration  on  a  large  scale,  through 
sand  and  gravel,  was  first  done  in  London,  in  1839,  when 
one  of  the  city  water  companies  subjected  the  water  it  was 
furnishing  to  the  city  to  this  process  in  order  to  remove 
turbidity.  It  is,  however,  only  during  the  last  decade 
that  the  matter  of  sand  filtration  has  received  a  great  deal 
of  attention.  Experiments  have  been  made  on  large  and 
small  scales,  from  which  many  important  facts  regarding 
such  filters  have  been  obtained.  It  has  been  found  that 
even  raw  sewage  can  be  treated  in  this  way  with  remark- 
able results,  and  in  water  98  to  99  per  cent,  of  the  bacteria 
and  a  large  proportion  of  the  organic  matter  are  removed. 

Sand  filtration  is  spoken  of  as  intermittent  or  contin- 
uous, depending  on  the  fact  whether  water  is  kept  on  the 
filter  continuously  or  not.  The  continuous  filter  is  most 
useful  in  the  following  instances:  When  a  city  requires 
all  the  water  a  filter  will  take  care  of  when  running  con- 
tinuously; when  the  water  is  not  greatly  polluted;  and 
when  the  conditions  of  temperature  in  winter  are  such  that 
a  certain  amount  of  water  must  be  kept  on  the  filter  bed  in 


ME  THODS  OF  PURIFICA  TION.  125 

order  to  prevent  freezing.  The  more  rapid  the  rate  of 
flow  through  the  filter,  the  more  impurities  the  filtered 
water  will  contain. 

hiterrnittent  filtration  is  resorted  to  when  the  water  is 
highly  polluted.  A  certain  amount  of  air  is  necessary  to 
complete  the  oxidation  of  the  organic  matter.  Highly 
polluted  water  is  deficient  in  dissolved  oxygen,  and  hence 
the  filter  must  be  ventilated  from  time  to  time  to  allow 
the  nitrifying  bacteria  to  recuperate.  ^Vhen  the  flow  of 
water  is  stopped  the  last  portion  of  water,  as  it  sinks 
down  into  the  filter,  draws  the  air  after  it,  thus  assisting 
in  the  aeration  of  the  filter. 

The  continuous  process  of  sand  filtration  is  used  suc- 
cessfully at  Altqna,  Hamburg,  Breslau,  Berlin,  Zurich, 
and  London,  in  Europe,  and  at  Lawrence,  Mass.,  Ber- 
wyn,  Pa.,  Nyack,  Poughkeepsie,  and  Albany  in  New 
York,  Superior  and  Ashland,  Wis.,  Washington,  D.  C, 
Pittsburgh,  Pa.,  and  at  Philadelphia,  Pa. 

The  Lawrence  filter  removes,  on  an  average,  98.3  per 
cent,  of  the  bacteria  contained  in  the  river-water.  The 
average  number  of  deaths  in  the  city  from  typhoid  fever 
in  previous  years  had  been  43  for  eight  months,  from 
October  to  May,  while  in  the  first  year  after  starting  the 
filter  there  were  only  16.  Of  the  16  who  died,  9  were 
operatives  in  the  mills,  and  were  known  to  have  used 
imfiltered  canal  water  for  drinking.  In  1898  there  were 
only  8  deaths  from  typhoid  fever,  a  death-rate  of  1.39  per 
10,000  persons  living. 

The  slow  sand  filters  for  the  purification  of  water  are 
located  on  ground  usually  elevated  somewhat  above  the 
level  of  the  river,  and  the  raw  water  is  pumped  on  the 
filters,  and  after  filtration  flows  by  gravity  to  a  basin,  from 
whence  it  is  carried  in  mains  to  the  area  to  be  supplied. 

In  Philadelphia  and  other  places  the  river  water  is  first 
passed  through  preliminary  filters,  v/here  much  of  the 
mud  and  the  grosser  impurities  are  removed.  These  pre- 
liminary filters  are  constructed  of  crushed  stones  and 
coarse  sand,  through  which  the  water  passes  by  gravity 


126  WATER  AND   WATER-SUPPLY. 

at  a  rapid  rate.  These  filters  serve  merel}^  as  strainers, 
as  the  water  passes  through  too  rapidly  to  undergo  bio- 
logical purification.  When  the  loss  of  head  in  these 
filters  has  reached  a  point  where  experienca  has  shown 
that  it  is  necessary  to  clean  them  the  filtration  is  arrested. 
The  filters  are  cleaned  by  forcing  up  through  the  bed  a 
current  of  compressed  air  to  break  up  the  layer  of  foreign 
material  that  has  accumulated  on  the  surface,  after  which 
a  reverse  current  of  water  is  forced  up  through  the  filter 
to  wash  the  accumulated  filth  into  drains  which  carry  it 
to  a  sewer.  These  filters  may  require  cleaning  each  day, 
depending  on  the  amount  of  suspended  matter  in  the  raw 
water. 

The  final  filters  are  of  different  construction.  The 
filter  bed  is  underdrained,  and  over  these  drains  the  fil- 
tering material  is  placed,  and  consists  of  a  layer  of  stone 
and  then  coarse  sand  to  a  depth  of  about  a  foot  and  a 
layer  of  fine  sand  to  a  depth  of  three  or  four  feet.  The 
water  coming  from  the  preliminary  filters  flows  by  gravity 
on  to  the  surface  of  the  sand  of  the  final  filters  and  passes 
throuofh  the  filter  bed  into  the  underdrains  and  from  these 
to  the  filtered  water  basin.  The  size  of  the  sand  grains 
and  the  amount  of  head  given  to  the  water  over  the  sur- 
face of  the  filter  bed  is  governed  by  the  character  of  the 
results  obtainable  under  the  local  conditions. 

The  final  filters  act  merely  as  strainers  when  the  water 
is  first  applied,  and  several  weeks  to  a  month  must  usually 
elapse  before  the  effluent  is  purified  to  a  satisfactory  de- 
gree. When  this  stage  has  been  reached,  an  examination 
of  the  surface  of  the  filter  bed  shows  that  a  slimy  layer 
has  collected  on  top  of  the  sand  and  penetrates  to  a  depth 
of  several  inches.  This  layer  is  composed  of  the  foreign 
material  in  the  water  and  a  felt-like  mass  composed  of 
bacteria,  algae,  and  other  living  organisms.  These  or- 
ganisms are  the  active  purifying  agents,  and  bring  about 
the  biological  purification  of  the  water.  The  principal 
agents  concerned  in  the  purification  of  the  water  are  the 
nitrifying  bacteria  which  were  brought  to  the  filter  in  the 


ME  THODS  OF  PUR  I  PICA  TION.  1 27 

applied  water  and  have  multiplied  on  top  of  and  in  the 
upper  layers  of  the  sand  composing  the  filter. 

As  the  amount  of  filth  collecting  on  the  filter  increases 
in  thickness,  decreasing  amounts  of  water  pass  through 
until  finally  the  amount  of  pure  water  obtained  is  so 
small  as  to  render  the  filter  unprofitable.  When  this 
stage  is  reached  the  filter  is  cleaned.  The  cleaning  oper- 
ation of  the  final  filters  is  accomplished  by  allowing  all 
the  water  to  drain  off,  and  then  with  shovels  the  filth  and 
an  inch  or  two  of  the  upper  layer  of  the  sand  bed  are 
removed.  This  material  is  then  removed  from  the  filter 
and  passed  through  a  sand  washing  machine.  These 
washing  machines  are  now  so  constructed  that  they  can 
be  placed  on  the  surface  of  the  scraped  filter  and  the  filth 
and  dirty  sand  are  shoveled  into  the  machine  and  washed 
with  a  stream  of  pure  water,  the  filth  being  carried  to 
the  outside  through  one  pipe  while  the  washed  sand  is 
allowed  to  flow  on  to  the  surface  of  the  filter  bed.  In 
this  manner  the  depth  of  sand  composing  the  filter 
diminishes  slowly  and  the  life  of  the  filter  is  very  much 
prolonged. 

After  a  filter  has  been  cleaned  the  effluent  is  impure 
until  such  time  as  is  necessary  for  the  re-formation  of  the 
slimy  layer  on  the  surface.  Until  the  effluent  reaches  a 
satisfactory  degree  of  purity  all  the  water  passing  through 
the  filter  is  allowed  to  flow  into  a  sewer  and  returns  to 
the  river. 

The  preliminary  filters,  as  well  as  the  final  filters,  are 
built  in  sections,  so  that  while  one  section  is  being  cleaned 
the  other  sections  continue  in  operation,  consequently 
only  a  portion  of  the  filtering  area  is  out  of  commission 
at  a  time,  and  the  remainder  of  the  area  is  in  undisturbed 
operation.  The  cleaning  of  the  final  filters  and  the  time 
required  until  they  again  operate  efficiently  amount  to 
about  15  per  cent.,  and  hence  the  filtering  area  must  be 
increased  to  that  extent  over  the  area  required  if  the 
filters  could  be  operated  continuously. 

The  effluent  of  the  final  filters  is  examined  daily  as  to 


128  WATER  AND  WATER-SUPPLY. 

its  bacterial  content  and  at  longer  intervals  as  to  its 
•chemical  nature.  It  is  possible  to  control  the  character 
of  the  work  performed  by  each  unit,  and  use  or  discard 
the  effluent  of  any  unit  whenever  its  character  is  satis- 
factory or  unsatisfactory. 

The  greater  part  of  the  purification  of  water  in  a  sand 
filter  is  carried  out  on  or  near  the  surface  of  the  filter. 
The  slimy  pellicle  which  forms  on  the  surface  of  the 
filter  is  composed  largely  of  so-called  bacterial  jelly,  and 
it  is  the  nitrifying  bacteria  in  this  pellicle  that  accom- 
plish the  purification.  The  efficiency  of  a  filter  is  very 
low  until  this  pellicle  has  had  time  to  form,  and  when  it 
is  removed  the  efficiency  of  the  filter  is  destroyed.  Aside 
from  this  surface  film,  or  "  schmutzdecke,"  as  the  Ger- 
mans call  it,  the  individual  sand  grains  in  the  upper 
portion  of  the  filter  are  also  covered  with  a  coating  of  a 
similar  nature. 

The  action  of  the  filter  as  a  whole  must  be  taken  into 
account.  There  is  undoubtedly  much  mechanical  work 
accomplished  in  the  actual  removal  of  the  larger,  trouble- 
some, but  not  particularly  dangerous  organisms,  and  of 
the  turbidity  and  sediment.  This,  however,  is  not  the 
most  important  action  of  the  sand  filter.  There  is  also 
a  chemical  action  going  on,  an  oxidation  or  burning  up 
of  the  organic  matter,  and  this  is  mainly  due  to  the  vital 
force  in  the  filter — the  nitrifying  bacteria.  These  organ- 
isms appear  to  be  antagonistic  to  water  bacteria  and  to 
pathogenic  organisms  present  in  water,  because  those 
organisms  are  almost  entirely  removed  in  an  efficient 
sand  filter. 

The  changes  which  take  place  in  the  water  as  the 
result  of  filtration  through  a  sand  filter  are  as  follows: 

Removal  of  solids  in  suspension loo  per  cent. 

Reduction  in  free  ammonia 50  to  75        " 

Reduction  in  albuminoid  ammonia 35  'o  5°       " 

Reduction  in  oxidizable  organic  matter 25  to  30  ,     " 

Increase  in  nitrates 25  to  30       " 

The  rate  of  filtration  should  not  exceed  very  much  i  .5 


METHODS  OF  PURIFICA  TION. 


129 


cubic  meters  per  square  meter  of  surface,  though  it  may 
vary,   accordiug  to  the  relative  purity  of  the  unfiltered 
water,   from  2,000,000  to 
5,000,000  gallons  per  acre 
daily    (22,000    to    56,000 
cubic  meters  per  hectare). 
The  height  of  water  on 
the    sand    filters,    or   the 
amount  of  head,   as  it  is 
called,  in  the  continuous 
process  of  filtration  varies 
according  to  the  practice 
which  is  found  to  give  the 
best  results,   the  average      c 
depth  of  water  being  50     ^ 
to  75  centimeters,  though      ^1 
many  of  the  German  fil-      ^ 
ters  contain  as  much   as      - 

c 

100  to  125  centimeters.  \ 

The  efficiency  of  sand      ; 
filters    is    dependent,     to      c 
some    extent,     upon    the      : 
size  of  the  sand  particles      \ 
composing  the  filter.    The      : 
range  of  the  size  of  the 
sand  grains  is  from  0.09 
to  0.38  of  a  millimeter  in 
diameter.    Within  certain 
limits,  the  finer  the  sand 
particles   the   greater  the 
efficiency  of  the  filter. 

When  first  constructed, 
the  thickness  of  the  sand 
layer  ranges  from  f  to  \\ 
meters.  On  account  of  the  process  of  scraping,  which 
is  necessary  to  clean  the  filter  from  time  to  time,  the 
thickness  of  the  sand  layer  is  reduced,  and  authorities 
differ  as  to  the  extent  of  the  reduction  that  is  permissible  ; 
9 


130  WATER  AND   WATER-SUPPLY. 

some  allowing  a  reduction  to  a  depth  of  3  decimeters  ; 
others  contending  that  the  reduction  should  never  be 
greater  than  to  6  decimeters  before  the  sand  is  replaced. 
Fig.  24  shows  a  section  of  a  covered  sand  filter  such  as  is 
in  use  at  Albany,  N.  Y. ,  and  similar  in  form  to  those 
constructed  at  Philadelphia  and  Washington. 

In  cold  climates  it  is  necessary  to  cover  the  filters  in 
order  to  prevent  freezing.  In  warm  latitudes  the  filter 
should  be  covered  over  to  prevent  undue  heating  of  the 
water.  It  is  also  advisable  to  cover  the  filters  in  order  to 
exclude  sunlight  and  thus  prevent  the  growth  of  algae, 
and  to  exclude  dust. 

The  efficiency  of  large  sand  filters  may  be  demon- 
strated, first,  by  a  reduced  mortality  from  typhoid  fever 
and  from  cholera  after  the  introduction  of  the  filter. 
The  bacterial  efiicienc}^  of  sand  filters  ranges  from  98.  i 
to  99.93  per  cent.  The  chemical  efficiency  of  some  of 
the  lyondon  filters  is  such  that  all  of  the  ammonia  is  re- 
moved, others  removing  from  75  to  80  per  cent.  In  each 
instance  the  total  solids  are  slightly  reduced,  the  organic 
carbon  and  organic  nitrogen  are  uniformly  reduced  ; 
showing  that  sand  filtration  effects  an  appreciable  reduc- 
tion in  the  amount  of  organic  matter. 

The  entire  city  of  Philadelphia  is  now  served  with  fil- 
tered water.  The  influence  of  the  filtered  water  on  the 
incidence  of  typhoid  fever  has  been  such  as  to  cause  a 
reduction  of  more  than  80  per  cent.  It  is  safe  to  assume 
that  most  of  the  typhoid  fever  now  occurring  in  the  city 
is  due  to  milk  infection  and  to  contact  cases. 

Rapid  sand  filtration^  was  first  introduced  at  Somer- 
ville,  N.  J.,^  in  1885.  Many  cities  and  towns  have  since 
adopted  this  method.  The  largest  plants  in  use  are  at 
Cincinnati,  O.,  Columbus,  O.,  Hackensack,  N.  J., 
Harrisburg,  Pa.,  Little  Falls,  N.  J.,  Louisville,  Ky., 
Toledo,  O.,  New  Orleans,  La.,  MinneapoHs,  Minn., 
and  Grand  Rapids,  Mich.     Filter  plants  of  this  nature 

1  George  A.  Johnson,  Water-supply  Paper,  No.  315,  Washington,  D.  C. 

2  The  Ohio  Public  Health  Journal,  Vol.  VII,   No.  11,  p.  436. 


ME  THODS  OF  PUR  I  PICA  TION.  131 

have  also  been  installed  at  Alexandria  and  Cairo,  Egypt, 
and  at  Tokio,  Japan. 

The  rapid  sand  filters  are  employed  in  the  purification 
of  waters  having  a  high  turbidity.  The  suspended  mat- 
ter in  these  waters  would  soon  clog  the  surface  of  a  slow 
sand  filter  and  so  render  it  useless.  In  the  rapid  sand 
filtration  process  coagulants  are  added  to  the  water  before 
filtration.  The  coagulant  most  commonly  employed  is 
aluminum  sulphate,  though  ferrous  sulphate  may  also 
be  employed,  but  is  more  expensive  and  less  efficacious. 
When  carbonates  are  also  present,  the  coagulant  added 
to  the  water  forms  a  soft,  flocculent  precipitate  which 
settles  on  the  surface  of  the  sand  and  forms  a  mat  which 
strains  out  all  suspended  matters  in  the  water,  including 
most  of  the  bacteria.  The  rate  of  filtration  is  about 
forty  times  as  great  as  in  the  slow  sand  filter,  and  hence 
there  is  no  chance  for  biological  purification  because 
this  method  of  filtration  is  dependent  upon  the  straining 
effect  of  the  precipitate  on  the  surface  of  the  sand.  The 
greater  the  amount  of  suspended  matter  in  the  water, 
the  quicker  the  filter  becomes  useless  from  the  accumula- 
tion of  matter  on  its  surface  and  the  more  frequently  the 
filter  has  to  be  cleaned.  These  filters  are  cleaned  by 
forcing  filtered  water  up  through  the  filtering  material 
and  carrying  the  mud  and  impurities  into  a  sewer. 
After  a  filter  has  been  cleaned  the  water  which  passes 
through  it  is  at  first  grossly  polluted,  and  only  becomes 
fit  for  use  when  a  sufficient  amount  of  precipitate  has 
been  deposited  on  the  surface  of  the  sand  to  serve  as  an 
efficient  strainer. 

In  addition  to  the  use  of  the  coagulant,  other  chemicals 
may  also  be  used  to  soften  the  water,  as  is  done  at 
Columbus,  Ohio,  and  other  places  where  the  hardness 
of  the  treated  water  makes  such  treatment  desirable. 

This  type  of  filter  is  usually  constructed  of  a  number  of 
small  units,  and  additional  units  are  added  as  the  town 
grows  in  population.    The  initial  cost  of  the  rapid  sand 


132 


WA  TER  AND   WA  TER-SUPPL  Y. 


filters  is  lower  than  that  of  the  slow  sand  filters,  but  the 
expense  of  operation  is  higher.  The  water  purified 
by  the  rapid  sand  filtration  method  is  of  satisfactory 
sanitary  quality  provided  the  process  is  carried  out 
properly. 

Water  purification  plants  have  multiplied  very  rapidly 
in  thickly  populated  communities  within  the  last  decade, 
so  much  so  that  in  several  states  nearly  one-half  of  the 
total  population  is  receiving  water  that  has  been  purified 
in  one  way  or  another. 

Water  Filtration  Plants  in  Nine  States,  191 6.^ 


Number  of 
Plants. 

Total  Ca- 
pacity of 

plants, 
M.  G.  D. 

Population  Served. 

State. 

Total. 

Percentage 
of    Total 
Pop.  of 

State. 

Percentage 
of  Urban 
Pop.  of 

State. 

Pennsylvania 

Ohio 

123 
42 
68 
9 
38 
17 

7 

900 
465 

139 

no 

88 

34 
26 

45 

3,960,000 
2,205,000 
825,000 
659,000 
500,000 
500,000 
326,000 
235,000 
227,000 

46.7 

43 -o 

8.1 

48.5 

8.2 

17.8 

14.4 

8.1 

7-S 

75-5 
72.3 
10. 0 

94- S 
126 

New  York 

Maryland 

Illinois 

Indiana 

41.4 
33-0 

Minnesota 

California. .  . 

7 

6 

Michigan 

14.7 

Numerous  mechanical  filters  are  now  on  the  mar- 
ket which  permit  the  rapid  filtration  of  large  volumes 
of  water  through  limited  sand  areas,  and,  in  most 
instances,  under  considerable  pressure.  A  number 
of  these  mechanical  filters  make  use  of  some  coagu- 
lant, such  as  alum  or  iron,  in  order  to  assist  in  clari- 
fying and  purifying  the  water.  The  flocculent  pre- 
cipitate which  is  formed  takes  with  it  the  suspended 
matters  as  well  as  the  bacteria,  and  the  whole  mass  is 
caught  on  the  surface  of  the  sand  as  the  water  passes 
through.  Usually  these  filters  are  cleaned  by  turning 
the  water  in  the  reverse  direction,  thus  washing  the 

1  The,  Ohio  Public  Health  Journal,  vol.  vii.,  No.  11,  p.  436. 


METHODS  OF  PURIFICATION. 


133 


filth,  which  has  accumulated  on  the  sand,  into  the  sewer. 
Small  filters  of  this  nature  are  employed  to  filter  the 
water  of  manufacturing  establishments,  of  hotels,  hos- 
pitals, and' of  private  dwellings  (see  Fig.  25);  larger  sizes 
arranged  in  series,   are  now  also  employed  to  filter  the 


K.    Q- 


Fig.  25. — Mechanical  filter  :  A,  inlet  pipe ;  B,  outlet  pipe ;  C,  waste  pipe ; 
D,  valve  to  cut  off  water  from  filter ;  E,  lever  to  operate  the  agitator ;  F,  air 
valve ;  H,  handle  of  valve  used  to  change  the  course  of  the  water  through  the 
filter;  I,  distal  attachment  of  coagulating  tank  to  inlet  pipe;  K,  lever  valve 
regulating  the  quantity  of  alum  supplied ;  O,  proximal  attachment  of  coagulating 
tank  to  inlet  pipe ;  P,  waste  pipe  leading  from  the  coagulating  tank  to  the 
sewer ;  Q,  valve  which  fastens  on  the  cover  of  the  coagulating  tank ;  S,  pointer 
which  indicates  the  course  of  the  water  through  the  filter ;  T,  sight  glass. 

water  of  municipalities  where  the  nature  of  the  impuri- 
ties in  the  water  makes  it  impossible  to  obtain  satisfactory 
results  by  sand  filtration,  A  great  deal  of  objection  has 
been  raised  by  persons  not  fully  informed  on  the  subject, 
against  the  use  of  alum  as  a  coagulant.  If  the  alum  is 
used  intelligently,  there  is  not  the  slightest  danger  from 
its  ifSe.  It  is  converted  into  aluminum  hydroxid,  a  white 
flocculent  precipitate,  and  is  retained  on  the  surface  of 
the  sand  in  this  form.  Unless  unusual  amounts  are  used, 
none  of  it  will  be  found  in  the  filtered  water. 

Another  form  of  mechanical  filter  in  use  is  that  in 
which  spongy  iron  and  scrap  iron  are  used  as  coagu- 


1 34  WA  TER  AND   WA  TER-SUPPL  V. 

lants.  In  these  filters  there  is  an  additional  item  of 
expense  in  the  revolving  machinery  which  is  necessary 
to  agitate  the  iron  in  the  water.  The  scrap  iron  is 
contained  in  a  revolving  cylinder  through  which  the 
water  passes.  After  passing  through  this  cylinder  the 
water  flows  on  to  a  sand  filter.  This  process  is  not 
adapted  to  the  purification  of  brown,  peaty  waters, 
because  the  iron  forms  a  soluble  compound  with  the 
organic  matter  in  these  waters.  A  mechanical  filter 
of  this  kind  has  been  in  successful  operation  at  Wil- 
mington, Del.,  for  some  years,  and  at  Quincy,  111. 

The  nature  of  the  water  and  soil  of  a  locality  influ- 
ences the  kind  of  purification  that  will  be  most  efiEicient. 
This  can  only  be  determined  by  a  series  of  systematic 
tests.  Such  tests  and  studies  have  now  been  made  at 
Louisville,  Cincinnati,  Providence,  St.  Louis,  Pittsburg, 
Columbus  and  Lorain,  Ohio,  Washington,  D.  C,  and  at 
Philadelphia. 

No  city  should  be  satisfied  unless  it  possesses  the  best 
possible  water-supply.  The  importance  of  having  a  sup- 
ply of  pure  water  must  be  evident.  A  municipality 
should  be  compelled  to  furnish  its  citizens  with  a  water- 
supply  which  does  not  need  house  filtration  nor  boiling 
to  render  it  safe.  The  insurance  companies  have  brought 
the  matter  to  a  focus  by  making  the  quality  and  quantity 
of  a  municipal  water-supply  one  of  the  factors  in  deter- 
mining the  insurance  rates.  The  life-insurance  rates 
are  sometimes  increased  if  the  water  is  polluted,  and  the 
fire  rates  are  increased  if  the  quantity  of  the  general 
water-supply  is  considered  insufiicient.  One  or  more 
such  cases  of  increased  rates  have  occiu'red  recently  in 
the  State  of  Indiana.  No  problem  connected  with 
modern  municipal  Hfe  is  of  greater  vital  importance 
than  the  pinrification  and  protection  of  the  water-supply. 

The  attention  which  has  been  given  to  the  purifica- 
tion of  water-supphes  has  produced  remarkable  results 
with  regard  to  the  conservation  of  the  health  of  people 
living  in  urban  communities.     These  effects  are  seen 


ME  THODS  OF  PURIFICA  TION. 


135 


especially  in  the  progressive  reduction  in  the  death-rate 
from  typhoid  fever.  The  figures  in  the  following  table 
have  been  collected  by  the  Journal  of  the  American 
Medical  Association: 


Typhoid  in  Cities  of  the  United  States  in  191 6. 

{Jour.  Amer.  Med.  Assoc,  March  17,  1917,  Vol.  Ixviii,  No.  11,  p.  845.) 
GROUP  1   (OVER  500,000  POPULATION). 
Deaths  from  Typhoid  per  100,000 

Population.  Average,  Average, 

1916.                     1915.  1911-1915.  1906-1910. 

Boston 3.5                   5.5  8.0  16.0 

New  Ycrk 3.8                   6.0  8.0  13.5 

Chicago 5.2                   5.4  8.2  15.8 

Cleveland 5.3                    7.8  lo.o  15.7 

Philadelphia 7.8                   6.6  11. 2  41.7 

Pittsburgh 8.6                  10.3  15.9  65.0 

St.  Louis 9.4                   7.0  12. 1  14.7 

Detroit 15.0                 12.8  18.1  21. i 

Baltimore 18.0                 21.9  23.7  35.1 

GROUP  2  (FROM  300,000  TO  500,000  POPULATION). 

Seattle 3.0                  2.5  5.7  25.2 

Los  Angeles 3.1                   5.5  10.7  19.0 

Cincinnati 3.4                   7.8  7.8  30.1 

San  Francisco 3.4                   9.4  13.6  27.3 

Newark,  N.  J 5.3                   2.5  6.8  14.6 

Minneapolis 5.8                   7.1  10.6  32.1 

Buffalo 10.9                   9.9  15.4  22.8 

Washington,  D.C..  .  .          12.6                 11. 7  i7-2  36.7 

Milwaukee,  Wis i4-9                   4-5  i3-6  27.0 

NewOreleans 23.4                 21.5  20.9  35.6 

GROUP  3  (FROM  200,000  TO  300,000  POPULATION). 

Portland,  Ore 4-6                   5-2  10.8  23.2 

St.  Paul 4-0                   7-4  9-2  18.3 

Providence,  R.  1 5.1                   8.4  10.2  14.3 

Rochester,  N.  Y 5.1                   6.0  9.6  12.8 

Jersey  City,  N.  J 6.8                  5.6  7-2  12.6 

Denver 7*2                   6.6  12.0  37.5 

Louisville,  Ky 9.7                 12.0  19.7  52.7 

Kansas  City,  Mo 10.6                   7.2  16.2  35.6 

Columbus,  Ohio 13.4                 i3-3  iS-8  40.0 

Indianapolis 26.6                 12.3  20.5  30.4 


136 


IVA  TER  AND  WA  TER-SUPPL  Y. 


GROUP  4  (FROM  125,000  TO  200,000  POPULATION). 
Deaths  from  Typhoid  per  100,000 
Population. 


1 

1916. 

Paterson,  N.  J 

1.4 

Spokane,  Wash 

2.0 

Worcester,  Mass 

3-7 

Oakland,  Cal 

4.0 

Omaha .' .  .  . 

5-1 

Scranton,  Pa 

5-4 

New  Haven,  Conn. .  . 

8.0 

Fall  River,  Mass 

10.9 

Syracuse,  N.  Y 

12.2 

Atlanta,  Ga 

17.9 

Toledo,  Ohio 

22.9 

Richmond,  Va 

24.1 

Memphis,  Tenn 

36.3 

Birmingham,  Ala. .  .  . 

42.6 

GROUP  5  (FROM 

Cambridge,  Mass. .  .  . 

0.9 

Tacoma,  Wash 

Z-$ 

New  Bedford,  Mass. . 

4.2 

Springfield,  Mass. .  .  . 

4-7 

Trenton,  N.  J 

6.3 

Hartford,  Conn 

6.3 

Albany,  N.  Y 

7-7 

Bridgeport,  Conn. .  .  . 

9.0 

Salt  Lake  City 

10.2 

Camden,  N.  J 

"•3 

Lowell,  Mass 

11.4 

Dayton,  Ohio 

14.7 

Grand  Rapids,  Mich. 

15.6 

San  Antonio,  Texas. . 

16.9 

Reading,  Pa — 

18.7 

Nashville,  Tenn 

27-3 

Dallas,  Texas 

27-S 

Average, 

Average, 

1915- 

1911-191S. 

1906-1910 

5-1 

9.1 

19-3 

10.7 

17. 1 

50-3 

5-6 

5-0 

11.8 

6.7 

8.7 

21.5 

3-7 

14-9 

40.7 

10.4 

9-3 

31-5 

18.3 

19.2 

30.8 

11.8 

13-4 

13-5 

5-9 

12.3 

15-6 

II. I 

31-4 

58.4 

23-9 

314 

37-5 

12.7 

iS-7 

34-0 

24.6 

42.5 

35-3 

33-7 

)  125.000  POPULATION). 

1.8 

4.0 

9.8 

5-5 

10.4 

18.2 

15.0 

16.1 

10.6 

17.6 

6.4 

22.3 



18.3 

15-9 

19.0 

12.6 

18.6 

17.4 

5-1 

5-0 

10.3 

7.0 

13.2 

6.7 

4-S 

16.0 

10.2 

13-9 

13.6 

14.8 

22.5 

24.6 

25-5 

29.7 

19.2 

29-5 

16.2 

31-9 

42.0 

35-1 

40.2 

61.2 

20.3 

Household  Filters. — Household  filters  may  be  divided 
into  two  large  classes,  those  which  filter  all  the  water 
supplied  to  a  house,  as  small  forms  of  the  different  types 
of  mechanical  filters,  and  those  which  filter  only  the 
portion  used  for  cooking  and  for  drinking  purposes.  A 
variety  of  filters  is  now  on  the  market  that  is  intended 
for  this  purpose.  The  essential  characteristics  of  a  good 
filter  of  the  latter  class  may  be  stated  as  follows : 


METHODS  OF  PURIFICATION. 


m 


A.  With  regard  to  the  filtering  medium: 

1.  It  should  have  sufficient  purifying  power,  mechan- 
ically, to  restrain  all  suspended  matters ;  chemically,  to 
remove  dissolved  organic  or  deleterious  matter ;  and 
biologically,  to  arrest  micro-organisms. 

2.  This  purifying  power  should  be  reasonably  lasting. 

3.  The  filtering  medium  should  give  up  to  the  water 
nothing  that  is  either  itself  del- 
eterious or  that  will  favor  the 
growth  of  low  forms  of  life. 

4.  The  delivery  should  be 
reasonably  rapid,  consistent 
with  efficient  purification. 

B.  With  regard  to  the  filter 
construction  : 

5.  It  should  be  so  constructed 
as  to  be  easily  taken  apart,  in- 
spected and  cleaned. 

6.  There  should  be  nothing 
that  is  liable  to  decay  or  ca- 
pable of  yielding  up  metallic  or 
other  impurities  to  the  water. 

The  domestic  filters  of  this  class  which  meet  all  these 
conditions  most  satisfactorily  are  the  Berkefeld  filter  (see 
Fig.  26),  composed  of  cylinders  of  baked  infusorial  earth, 
and  the  Pasteur  filter,  composed  of  cylinders  of  baked, 
unglazed  porcelain.  These  filters  yield  a  water  that  is 
clear  and  sparkling,  free  from  bacteria,  and  are  readily 
taken  apart  and  cleansed.  After  having  been  in  use  for 
several  days  the  filtered  water  begins  to  show  the  presence 
of  bacteria  owing  to  the  fact  that  these  organisms  have 
grown  through  the  pores  of  the  filter.  For  this  reason 
these  filters  must  be  cleansed  at  frequent  intervals.  This 
cleansing  should  consist  in  scrubbing  the  outside  of  the 
cylinder  and  then  boiling  or  baking  for  an  hour.  After 
such  a  cleansing  they  are  almost  as  efficient  as  new 
filters. 

Purification  of  Water  without  Filtration The  proc- 


FiG.  26. — Domestic  filter—* 
Berkefeld :  a,  point  of  attachment 
to  faucet ;  d,  outlet. 


138  WATER  AND   WATER-SUPPLY. 

esses  of  purification,  aside  from  filtration,  which  may 

be  employed,  are  distillation,  boiling,  and  treatment  with 

chemical    substances.      Distillation.,    if   properly  carried 

out,   furnishes  a  pure  water.     It  is,    however,   deprived 

of  its  oxygen  and  carbonic  acid,  and  consequently  it  is 

tasteless.     To  remedy  this  defect   a   number  of  special 

distilling  apparatuses  have  been  devised  which  aerate  the 

water  at  the  same  time  (see  Fig.  27). 

Boiling.,  next  to  distillation,  furnishes  a  harmless  water, 

though  it  does  not  remove  the  dissolved  impurities,  and 

at  the  same  time  it  removes  the 

^^Sli^^^^j  gases   dissolved   in   the  water. 

B|jj|,|b^  11^  It  renders  the  water  tasteless. 

Bi  11^^^^     H  Boiled  water  may  be  aerated  to 

W^^f  ~^'^'^wM  some  extent  by  pouring  it  from 

K^n^FK^^pi  ^^^  vessel  to  another.      Boiling 

B^^llf^^TB  removes    the    temporary    hard- 

KjIIII Ife^MIJi  ness,  the  hydrogen  sulphid,  and 

1^  ^         .       ^       .,,        renders    the   dissolved    organic 

Fig.  27. — Domestic  water  still.  _  ^ 

matter  and  bacteria  harmless. 

Where  a  water  is  objectionable  merely  on  account  of 
the  bacteria  contained  in  it,  and  there  is  danger  of  con- 
tracting one  or  the  other  of  the  water-borne  diseases,  a 
satisfactory  mode  of  domestic  purification  is  that  by 
means  of  the  Forbes  water  sterilizer  (Figs.  28  and  29),  in 
which  the  water  is  boiled  and  cooled  during  its  passage 
through  the  apparatus,  issuing  from  the  apparatus  with 
its  temperature  but  little  higher  than  at  the  point  of 
entrance. 

The  treatment  of  water  by  means  of  chemical  sub- 
stances is  conducted  with  the  object  of  precipitating 
suspended  matters,  as  by  means  of  the  salts  of  alumi- 
num; the  removal  of  hardness,  by  the  addition  of  lime; 
to  oxidize  the  organic  impurities  present,  by  the  addition 
of  potassium  permanganate ;  the  removal  of  pathogenic 
bacteria,  as  in  the  treatment  with  ozone,  bromin,  or 
hypochlorites. 

Crystallized  alum  is  very  efiectual  in  the  precipitation 


METHODS  OF  PURIFICATION. 


139 


Fig.  28. — Forbes'  portable  water  sterilizer,  for  use  in  the  absence  of  a  general 
water-supply.  The  raw  water  is  supplied  from  the  inverted  bottle  I.  The 
water  runs  from  the  bottle  i  into  the  cup  2,  then  down  through  the  pipe  3  into 
the  compartment  4  of  the  heat  exchange,  which  it  fills.  When  compartment  4 
is  filled,  the  water  runs  into  the  heater  5,  and  rises  in  the  pipe  6  to  the  level  X, 
where  it  stops.  No  more  water  will  now  run  out  of  the  bottle  I,  because  its 
mouth  is  sealed  by  the  water  in  the  cup  2  at  the  level  X.  The  burner  7  is  now 
lighted,  and  heat  is  applied  under  the  heater  5,  which  causes  the  water  in  the 
heater  to  boil,  and  in  boiling  it  rises  in  the  pipe  6  and  flows  over  into  cup  8, 
just  as  a  pot  on  a  cooking  range  will  boil  over.  It  is  therefore  impossible  for 
any  water  to  pass  through  the  apparatus  until  it  has  boiled,  for  it  is  only  by 
boiling  that  it  can  rise  sufficiently  in  the  pipe  6  to  flow  over  into  the  cup  8.  The 
water  continues  to  boil  over  into  the  cup  8,  and  quickly  fills  compartment  9  of 
the  heat  exchange.  When  compartment  9  is  filled,  the  water  runs  out  of  the 
pipe  II  at  the  opening  12  into  the  receiving  bottle  13.  While  passing  down 
through  the  compartment  9  the  heat  of  the  water,  which  is  boiling  hot,  is  trans- 
ferred, by  conduction,  through  the  thin  metal  partition  or  diaphragm  10  to  the 
cold  water  passing  up  through  compartment  4,  so  that  the  water  which  is  boiled 
in  the  heater  5  passes  out  of  the  apparatus  nearly  as  cold  as  that  entering, 
while  the  cold  water  entering  the  apparatus  becomes  heated  as  it  passes  up 
through  compartment  4,  and  reaches  the  heater  5  nearly  at  the  boiling-point. 


140 


WA  TER  AND   WA  TER-SUPPL  Y. 


of  suspended  matters  in  the  propotion  of  5  or  6  milli- 
grams to  the  liter  of  water.  The  action  is  most  marked 
if  calcium  carbonate  is  present.     Calcium  sulphate  is 


Fig.  29. — Forbes'  stationary  water  sterilizer.  The  principle  of  operation  of 
this  apparatus  is  identical  with  that  of  the  apparatus  shown  in  Fig.  28,  but  the 
construction  is  slightly  different.  In  this  apparatus,  i  shows  a  water  tank  with 
a  pipe,  2,  through  which  water  enters,  and  is  allowed  to  fill  the  tank  up  to  the 
water  level  X,  but  no  higher,  as  it  is  restrained  by  the  float-actuated  valve 
shown  in  the  tank. 

The  small  tank  with  the  float  and  valve  merely  take  the  place  of  the  inverted 
bottle  and  aerostatic  feed  used  in  the  first  apparatus.  Both  the  aerostatic 
device  and  the  float  and  valve  have  the  same  functions,  viz.,  maintaining  the 
water  level  at  the  line  X.  In  the  second  apparatus  the  pipe  2  is  connected  with 
a  constant  water-supply,  such  as  a  faucet  or  the  water-supply  pipe  of  the  house. 

After  the  water  leaves  the  float  box  it  runs  down  through  the  pipe  3,  and  the 
action  of  the  apparatus  from  this  point  on  is  exactly  like  that  of  the  porta- 
ble sterilizer  shown  in  Fig.  28. 

formed,  and  a  bulky  precipitate  of  aluminum  hydoxid 
which  carries  down  the  suspended  matters.  The  water 
may  then  be  filtered  or  on  subsiding  the  clear  water  may 
be  decanted. 


STERILIZATION  OF  WATER  BY  CHEMICALS.   141 

Softening  of  Hard  Waters. — Water  is  softened — that  is 
deprived  of  its  temporary  hardness — by  the  addition  of 
lime-water.  The  lime  combines  with  the  carbon  dioxid 
existing  free  in  the  water,  forming  calcium  carbonate. 
This  is  precipitated  together  M'ith  the  calcium  carbonate 
and  magnesium  carbonate  previously  existing  in  solution, 
because  they  are  rendered  insoluble  by  the  removal  of 
the  free  carbon  dioxid. 

At  Winnepeg,  Manitoba,  the  following  results  were 
obtained : 

Untreated.  Treated. 

Calcium 91'5  2\.\ 

Magnesium       67.6  42.8 

Sodium 167.2  167.8 

Iron  and  Aluminum .  Trace  Trace 

Silicic  acid 7.3  4.2 

Sulphuric  acid 172.9  172-4 

Chlorin 242.0  242,0 

Hardness,  as  CaCOj 510.4  231. 1 

The  hardness  of  the  water  due  to  other  salts  of  calcium 
and  magnesium  is  not  affected  by  this  treatment.  The 
reaction  which  takes  place  on  the  addition  of  lime-water 
is  as  follows  : 

CaH^Og  +  CaCOgCO^  =2CaC03  +  H20 
2CaH202  +  MgCOgCOa  =  2CaC03+  MgH^Oj. 

Great  care  must  be  exercised  in  regulating  the  amount 
of  lime-water  added  to  a  hard  water.  This  amount  can 
be  determined  only  by  chemical  tests.  . 

Carbonate  of  sodium  is  efficacious  for  softening  water 
for  washing  purposes,  but  it  is  unsuitable  for  water  used 
for  drinking  purposes,  as  it  leaves  an  unpleasant  taste. 
Soda-ash  combined  with  caustic  lime  is  used  for  the  soft- 
ening of  water  for  boiler  purposes  for  the  removal  of  sul- 
phates and  chlorids. 

Sterilisation  of  Water  by  Means  of  Chemicals. — 
A  large  number  of  chemicals  have  been  recommended 
for  the  sterilization  of  water,  namely,  alum,  lime,  salt, 
potassium  and  calcium  permanganate,  sulphate  of  iron. 


142  WA  TER  AND   WA  TER-SUPPL  V. 

chalk,  cholorid  of  iron,  chlorid  of  lime,  acetic  acid,  citric 
acid,  formalin,  snlphuric  acid,  alcohol,  chloroform,  iodin, 
chlorin,  bromin,  ozone,  sulphate  of  copper,  hypochlorites, 
etc.  Upon  bacteriologic  experimentation  it  has  been 
found  that  some  of  these  are  without  any  effect,  while 
others  require  a  very  long  time  for  their  action.  Many 
of  them  are  objectionable  on  account  of  the  fact  that  they 
discolor  the  water  or  alter  its  taste  and  odor  in  such  a 
manner  as  to  render  the  water  unsuitable  for  domestic 
use.  The  more  these  facts  are  borne  in  mind,  the  smaller 
the  number  of  chemicals  that  can  be  used  satisfactorily 
for  the  sterilization  of  water,  and  in  practice  only  the 
following  have  proved  serviceable — namely,  chlorin, 
bromin,  and  ozone.  The  use  of  chlorin  for  the  dis- 
infection of  water  has  found  application  in  a  number  of 
localities  where  other  methods  of  purification  were  not 
available.  The  chlorin  is  added  in  the  form  of  calcium 
hypochlorite  in  amounts  ranging  from  2  to  10  mg.  of  free 
chlorin  per  liter  of  water  (five  to  ten  pounds  of  hypo- 
chlorite of  lime  to  a  million  gallons  of  water).  A  con- 
tact of  about  two  hours  should  be  allowed  for  the  action 
of  the  chlorin.  The  amount  of  calcium  hypochlorite 
employed  should  be  carefully  regulated  in  accordance 
with  the  amount  of  organic  matter  in  the  water.  Ex- 
cessive quantities  of  the  disinfectant  are  to  be  avoided, 
not  only  because  of  the  possible  detrimental  effects  of  the 
chlorin,  but  also  because  of  the  needless  expense, 

A  number  of  cities  are  using  hypochlorites  of  lime  or 
soda  for  the  treatment  of  their  water-supplies.  In  some 
instances  the  chemical  is  added  to  unfiltered  water  that  is 
satisfactory  except  in  its  bacterial  content.  In  other 
cities  the  chemical  is  added  intermittently  to  the  effluent 
of  filter  plants  when  the  rate  of  filtration  is  pushed  to 
such  an  extent  as  not  to  permit  satisfactory  purification. 

Bromin  is  used  in  the  form  of  potassium  bromid  solu- 
tion (60  mg.  free  bromin  per  liter  of  water).  For  the 
removal  of  the  bromin  from  the  water  after  it  has  been 
acting  for  a  sufficient  length  of  time    the   addition  of 


WATER  FOR  BOILER-PURPOSES.  143 

ammonia  or  sodium  sulphate  or  sodium  carbonate  is 
required. 

Investigations  have  demonstrated  that  bromin  is  not 
capable  of  satisfactorily  sterilizing  water  when  applied 
on  a  large  scale.  Ozone  seems  to  sterilize  water  satis- 
factorily in  large  quantities.  This  rec^uires  electrical 
apparatus  such  as  is  constructed  by  Siemens  and  Halske. 
In  the  application  of  ozone  to  the  sterilization  of  water  it 
is  necessary  to  determine  definitely  the  quantity  of  oxi- 
dizable  matter  in  the  water.  The  larger  the  quantity  of 
such  matter,  the  greater  the  quantity  of  ozone  required, 
and  consequently  the  greater  the  cost  of  operation.  The 
relation  between  the  ozone  utilization  and  the  oxidizable 
matter  in  the  water  must  be  under  constant  control,  so 
that  an  excess  of  ozone  may  be  supplied  at  all  times. 
The  ozone,  when  present  in  sufficient  quantities,  kills  all 
bacteria  in  the  water  without  in  the  least  aSectinsf  the 
taste,  odor,  or  color  of  the  water,  and  the  excess  of  ozone 
remaining  in  the  water  after  the  sterilization  disappears 
in  a  short  time.  This  method  of  purification  is  expensive 
and  requires  constant,  intelligent  oversight. 

Disinfection  of  Water  with  the  Ultra-violet  I^ight. 
The  application  of  the  ultra-violet  rays  to  the  disinfection 
of  water  is  made  possible  by  the  Westinghouse  sterilizer. 
In  this  apparatus  the  water  streams  through  a  chamber 
in  which  it  is  exposed  to  the  ultra-violet  rays  generated 
with  a  mercury-quartz  lamp.  Studies  conducted  with  this 
apparatus  by  von  Recklinghausen  ^  show  that  with  the  use 
of  less  than  twenty-six  watt  hours  per  cubic  meter  of  water 
more  than  600  cubic  meters  of  water  could  be  disinfected 
in  twenty-four  hours,  and  frequently  the  water  was  steril- 
ized. All  colon  bacilli  were  killed,  v.  Recklinghausen 
believes  that  from  the  low  cost  for  operation  and  the 
high  efficiency  of  the  method  this  method  of  disinfecting 
water  has  a  bright  future. 

Suitability  of  Water  for  Boiler-purposes. — The 
suitability  of  water  for  boiler-purposes  is  largely  an  engi= 

^Gesundheits-Ingenieur,  34  Jahrg.,  191 1,  p.  166. 


144  WATER  AND   WATER-SUPPLY. 

neering  question,  though  it  is  also  of  importance  to  the 

householder,  because  the  conditions  are  the  same  in  the 
boiler  of  the  kitchen  range  or  of  the  heating  apparatus  as 
in  the  boiler  of  a  manufacturing  establishment.  Water 
may  be  unsuitable  for  boiler-purposes  on  account  of  its 
corroding  action'  or  on  account  of  scale-formation.  Water 
of  the  greatest  purity  is  not  always  the  best  for  boiler- 
purposes,  because  of  its  solvent  action.  This  corrosive 
action  may  be  increased  by  the  oxygen  and  carbon  dioxid 
in  solution  in  the  water.  The  corrosive  action  may  also 
be  due  to  the  presence  of  organic  and  mineral  acids  in 
the  water.  Waters  collected  from  swampy  regions  are 
usually  rich  in  organic  acids,  while  the  waters  derived 
from  mines  are  rich  in  mineral  acids.  Water  may  also 
possess  a  corrosive  action  because  of  the  presence  of 
soluble  chlorids,  especially  sodium  and  magnesium  chlo- 
rids.  Oils  may  also  favor  the  production  of  corrosive 
substances. 

The  corrosive  action  of  water  may  be  minimized  or 
prevented  by  the  removal  of  turbidity,  by  the  addition  of 
alkalies  to  neutralize  the  acidity,  heating  the  water  to 
drive  off  dissolved  oxygen,  while  the  action  of  the  soluble 
chlorids  may  be  prevented  by  the  addition  of  the  sub- 
stances which  will  be  described  as  useful  in  preventing 
scale- formation. 

The  ingredients  in  water  which  are  most  frequently 
concerned  in  scale-formation  are  the  salts  of  calcium  and 
magnesium.  The  amounts  of  silica  and  iron  are  rarely 
sufficient  to  cause  scale-formation  of  any  note.  The  most 
objectionable  salt  in  water,  with  regard  to  scale-forma- 
tion, is  calcium  sulphate. 

Scale-formation  is  prevented  by  the  neutralization  of 
the  carbon  dioxid  in  the  water.  This  acid  operates  in 
holding  the  calcium  and  magnesium  carbonates  in  solu- 
tion. The  carbon  dioxid  may  be  driven  off  by  heating 
the  water  before  it  passes  into  the  boiler,  so  as  to  precipi- 
tate a  portion  of  the  calcium  and  magnesium.  The  car- 
bon dioxid  may  also  be  neutralized  by  the  addition  of 


WA  TER  AND  SE  WAGE  ANAL  YSIS.  145 

slaked  lime  or  caustic  soda  to  the  water.  These 
will  combine  with  the  carbon  dioxid  and  precip- 
itate it  as  well  as  the  salts  of  calcium  and  magne- 
sium. 

Water  and  Sewage  Analysis. — Sanitary  analysis 
of  water  and  sewage  consists  of  a  microscopic  exami- 
nation, a  physical  and  chemical  analysis,  and  a  bacteri- 
ological analysis.  For  details  of  the  microscopic  ex- 
amination the  student  is  referred  to  Whipple's  book 
(Whipple,  "The  Microscopy  of  Drinking-water,"  Wiley 
&  Sons,  New  York,  1899).  For  details  of  methods  of 
the  chemical  and  physical  analysis  the  student  is  referred 
to  the  standard  methods  of  the  American  Public  Health 
Association  and  to  the  author's  "Handbook  of  Practical 
Hygiene"  (Bergey,  "Handbook  of  Practical  Hygiene," 
The  Chemical  Publishing  Company,  Kaston,  Penn- 
sylvania, 1899).  For  details  of  the  bacteriological 
analysis  the  student  is  referred  to  the  standard 
methods  of  the  American  Public  Health  Association 
and  to  Prescott  and  Winslow,  "Elements  of  Water 
Bacteriology." 

Collection  of  Samples. — In  each  instance  samples 
should  be  collected  in  colorless,  glass-stoppered  bottles 
that  are  scrupulously  clean.  For  the  bacteriological 
analysis  the  container  must  have  been  sterilized.  The 
sample  for  microscopic  examination  should  consist  of 
at  least  i  liter ;  that  for  the  chemical  and  physical  anal- 
ysis at  least  4  liters;  and  that  for  the  bacteriological 
analysis  at  least  200  c.c.  The  samples  should  be  col- 
lected with  great  care  so  as  to  avoid  surface  scum  or 
particles  on  the  surface,  as  well  as  sediment  deposited 
on  shore  of  streams  to  be  sampled.  For  shipment  the 
stoppers  and  necks  of  the  bottles  and  the  bottles  should 
be  covered  with  a  muslin  cap  and  the  bottles  should 
be  packed  in  cases  having  compartments  into  which 

the   bottles   fit   rather   closely.      These   compartments 

10 


146  WATER  AND   WATER-SUPPLY. 

should  be  lined  with  corrugated  paper,  felt,  or  other 
substance  so  as  to  prevent  breakage.  In  warm  weather 
or  when  shipment  is  to  be  made  over  a  considerable 
distance,  it  is  necessary  to  have  the  containers  packed 
in  ice  so  as  to  keep  the  temperature  as  low  as  possible 
to  prevent  multiplication  of  the  bacteria  and  alteration 
of  the  organic  matter  in  the  water. 

Microscopic  Examination. — The  microscopic  examina- 
tion should  be  carried  out  as  soon  as  possible.  In  no 
instance  should  the  sample  be  in  transit  for  more  than 
twenty-four  hours.  In  case  the  sample  contains  fragile 
organisms,  immediate  examination  is  advisable,  other- 
wise these  may  be  lost  when  the  water  has  been  shipped 
some  distance.  The  microscopic  examination  is  especi- 
allv  important  in  that  it  will  indicate  the  nature  of  the 
organisms  in  the  water  which  give  rise  to  various  odors 
in  water  that  may  be  wholly  satisfactory  as  far  as 
its  chemical,  physical,  or  bacteriological  content  may 
be  concerned.  According  to  Whipple  the  distinctive 
odors  produced  by  microorganisms  may  be  grouped 
around  three  general  terms — aromatic,  grassy,  and 
fishy. 

Physical  Examination. — The  physical  examination 
includes  observations  of  the  temperature,  color,  turbidity, 
odor  in  hot  and  cold  samples,  and  sediment. 

The  temperature  should  be  taken  at  the  time  of  col- 
lection. 

The  color  is  preferably  determined  by  comparison 
with  the  platinum-cobalt  standard  (Winslow  and 
Walker,  "Science,"  1907,  Vol.  26,  p.  675)  or  by  the 
United  States  Geological  Survey  Field  Method  which 
consists  in  comparing  the  color  of  the  water  with 
that  of  glass  disks  in  the  end  of  metallic  tubes.  This 
compares  very  favorably  with  the  platinum-cobalt 
method. 

The  turbidity  of  the  water  is  determined  by  comparing 


WA  TER  AND  SE  WA  GE  ANAL  YSIS.  147 

it  with  standards  prepared  by  suspending  silica  in  dis- 
tilled water. 

The  odor  should  be  noted  in  both  the  cold  sample 
and  the  sample  which  has  been  warmed  to  just  below 
the  boiling-point.  The  American  Public  Health  Associ- 
ation has  adopted  the  following  classification  of  amounts 
of  odors: 

Numerical 

Value.  Term.  Approximate  Definition. 

0  None.  No  odor  perceptible. 

1  Very  faint.        An  odor  that  would  not  be  detected  ordinarily  by  the 

average  consumer,  but  that  could  be  detected  in 
the  laboratory  by  an  experienced  observer; 

2  Faint.  An  odor  that  the  consumer  might  detect  if  his  atten- 

tion were  called  to  it,  but  that  would  not  attract 
attention  otherwise. 

3  Distinct.         An  odor  that  would  be  detected  readily  and  that 

might  cause  the  water  to  be  regarded  with  dis- 
favor. 

4  Decided.         An  odor  that  would  force  itself  upon  the  attention 

and  that  might  make  the  water  unpalatable. 

5  Very  strong.  An  odor  of  such  intensity  that  the  water  would  be 

absolutely  unfit  to  drink.     (A  term  to  be  used  only 
in  extreme  cases.) 


Pure  water  on  standing  shows  no  deposition  of 
sediment,  but  water  containing  matter  in  suspension 
will  show  varying  amounts  of  sediment  which  may  be 
termed  as  very  slight,  slight,  distinct,  decided.  In  the 
case  of  sewage,  considerable  sediment  will  be  formed 
on  standing. 

Chemical  Analysis. — The  determinations  that  are 
considered  necessary  for  a  satisfactory  sanitary  chemical 
analysis  of  water  or  sewage  are  as  follows:  residue  on 
evaporation,  total  and  dissolved,  with  the  loss  on  igni- 
tion in  some  instances;  total  nitrogen,  nitrogen  as  albu- 
minoid and  free  ammonia,  nitrites,  and  nitrates;  oxygen 
consumed;  chlorine;  dissolved  oxygen;  hardness;  alka- 


148  WA  TER  AND   WA  TER-SUPPL  Y- 

linity;  incrusting  constituents;  iron;  sulphuric  acid  and 
carbonic  acid.  For  details  of  the  methods  of  conducting 
these  determinations  the  reader  is  referred  to  the  texts 
already  announced.  The  importance  of  these  different 
constituents  varies  with  the  material  to  be  analyzed. 
In  the  analysis  of  surface  or  ground  waters  the  analyst 
is  especially  concerned  in  discovering  evidences  of  pol- 
lution, while  in  the  analysis  of  filtered  waters  he  is  inter- 
ested more  particularly  in  determining  the  stages  of  the 
process  of  purification  secured  by  the  plant  that  is 
being  studied.  In  the  analysis  of  sewage  he  is  in- 
terested in  determining  the  amount  of  decomposable 
material  still  present,  in  order  that  he  may  indicate 
to  what  extent  further  purification  may  be  necessary 
to  render  the  material  unobjectionable  when  finally 
disposed  under  the  conditions  prevailing  in  a  particular 
locality. 

Bacteriological  Analysis. — The  bacteriological  analysis 
of  water  may  consist  of  either  quantitative  determina- 
tions or  qualitative  determinations  of  the  bacteria  in 
the  water.  In  the  quantitative  analysis  water  is  plated 
on  standard  nutrient  agar  in  such  quantities  that  the 
plates  shall  have  not  more  than  about  200  colonies 
each  in  order  that  estimation  of  the  colonies  may  be 
made  quickly  and  accurately,  and  also  to  prevent  the 
inhibiting  action  of  neighboring  colonies  on  each  other. 
It  is  now  customary  in  most  laboratories  to  incubate 
the  plates  at  37.5°  C.  for  forty-eight  hours.  It  is  recog- 
nized that  at  this  temperature  the  typical  water  bac- 
teria are  excluded,  but  since  these  have  no  important 
sanitary  significance  and  as  time  is  an  important  element 
in  reaching  a  decision  as  to  the  character  of  the  water, 
it  is  generally  regarded  as  best  to  incubate  for  a  briefer 
period  at  a  higher  temperature  than  was  formerly  re- 
garded necessary.  Waters  that  contain  large  numbers 
of  bacteria  m.ust  first  be  diluted  with  sterilized  water 


WA  TER  AND  SE  WAGE  ANAL  YSIS.  149 

before  they  are  plated,  but  where  the  relative  number 
of  bacteria  cannot  be  known  it  is  advisable  to  plate 
several  dilutions,  say,  i  to  100,  i  to  1000,  i  to  10,000 
dilutions,  according  to  the  number  of  bacteria  suspected 
of  being  present.  In  the  analysis  of  sewage  even  higher 
dilutions  are  necessary. 

The  qualitative  analysis  of  water  may  take  several 
important  directions,  depending  upon  the  primary 
object  in  making  the  analysis.  The  water  is  usually 
placed  in  lactose-litmus  agar  in  order  to  ascertain  the 
number  of  acid-producing  colonies.  This  is  a  rough 
indication  of  the  number  of  organisms  of  the  colon 
group  contained  in  the  water.  Another  presumptive 
test  for  the  presence  of  the  colon  bacillus  consists  in 
inoculating  some  of  the  water  into  fermentation  tubes 
containing  lactose-bile  medium,  using  fractional  parts 
of  a  cubic  centimeter  so  as  to  reach  the  point  where  the 
water  is  diluted  to  such  an  extent  as  not  to  have  any  of 
the  fermenting  bacteria  in  some  of  the  dilutions  of  water 
inoculated.  For  water  which  contains  relatively  few 
organisms  of  the  colon  group  two  distinct  methods  of 
determining  this  fact  have  been  in  use:  First,  inocu- 
lating large  quantities  of  water,  say  50  c.c,  into  the 
lactose-bile  medium ;  second,  inoculating  10  c.c.  samples  in 
five  fermentation  tubes  containing  lactose-bile  medium. 
Pure  water  should  not  have  more  than  two  colon  bacilli 
in  100  c.c.  Where  the  number  of  colon  bacilli  is  much 
higher  than  this  there  is  presumptive  evidence  of  pol- 
lution of  untreated  water  or  imperfect  purification  of 
treated  waters.  The  qualitative  analysis  of  water  at 
times  also  calls  for  the  detection  of  some  of  the  specific 
bacteria  causing  gastro-intestinal  infection,  especially 
the  typhoid  bacillus  and  the  cholera  organism.  The 
detection  of  these  organisms  requires  the  use  of  special 
methods  for  the  enrichment  of  the  culture  whereby 
the  specific  organisms  are  caused  to  develop  and  the 


150  WATER  AND   WATER-SUPPLY. 

accompanying  bacteria  are  inhibited,  and  subse- 
quently the  enriched  culture  is  plated  out  on  special 
plate  media.  Details  of  these  methods  may  be  found 
in  the  standard  methods  of  the  American  Public 
Health  Association. 


CHAPTER     V. 
THE   REMOVAL   AND   DISPOSAL   OF   SEWAGE. 

The  term  sewage  includes  not  only  human  excreta, 
solid  and  liquid,  but  also  the  waste  water  and  impurities 
coming  from  human  habitations.  The  term  sewage, 
however,  does  not  include  such  impurities  as  proceed 
from  manufactories,  such  as  the  refuse  from  dye-works, 
gas-works,  etc. ;  these  are  termed  manufacturing  impuri- 
ties. From  a  hygienic  standpoint  the  human  excreta 
are  the  most  important  constituents  of  sewage.  The 
sewage  of  towns  usually  contains,  besides  human  excreta 
and  household  wastes,  the  water  used  for  washing  and 
sprinkling  streets,  as  well  as  the  rain  that  falls  which  is 
not  stored  for  household  use.  The  total  quantity  of 
sewage  depends  largely  upon  the  amount  of  pure  water 
supplied  per  head  per  day.  Sewage  has  an  average  com- 
position of  998  parts  of  water,  i  part  of  urine,  and  i 
part  of  organic  matter. 

The  Removal  of  Sewage. — The  removal  of  sewage 
from  the  dwelling  is  accomplished  by  several  different 
methods.  That  in  general  use  in  towns  is  by  means  of 
water.  This  system  necessitates  the  introduction  of 
the  necessary  waste  pipes  for  the  removal  of  the  sewage 
itself,  the  introduction  of  a  supply  of  water  sufficient  to 
flush  out  the  drain  pipes  and  keep  them  free  from  sewage. 
It  also  necessitates  arrangements  for  the  disposal  of  the 
sewage. 

Water-closets. — Where  water  is  employed  for  the  re- 
moval of  sewage  the  water-closet  forms  a  most  important 

151 


152   THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

factor  in  the  system.  The  quahties  required  by  all  the 
appliances  of  a  water-closet  are  durability,  simplicity, 
accessibility,  cleanliness,  and  general  effectiveness.    The 


Fig.  31. — Hopper  closet. 

principal  forms  of  closet  that  are  now  in  use  are  the 
hopper  (Fig.  31),  some  form  of  wash-out  or  wash-down 


Fig.  32. — Wash-out  closet. 


closet  for  private  dwellings  (Figs.  32,  33),  and  the 
trough  closet  or  latrine  for  schools  and  public  institu- 
tions. 


WATER-CLOSETS. 


153 


The  supply  of  water  for  the  wash-down  closet  is  obtained 
by  the  introduction  of  a  separate  cistern,  used  exclusively 
for   the    water-closet,   generally  termed   a    "water-waste 


Fig.  2i3- — Wash-down  closet. 

preventer ' '  (Fig.  34),  because  only  a  limited  supply  of 
water  is  available  for  delivery.  The  amount  of  water 
usually  supplied  in  the  cistern  is  about  15  liters.     The 


Fig.  34- — Water-waste  preventer. 

cistern  is  placed  at  some  height  (not  less  than  a  meter) 
above  the  closet,  and  has  an  exit  pipe  of  considerable 
size,  so  that  the  water  may  descend  with  sufficient  force 
to  flush  effectually  the  closet. 


154  THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

The  position  of  the  closet  chamber  is  of  importance. 
It  should  always  be  arranged  along  the  outer  wall  of  a 
building,  so  as  to  afford  ventilation  into  the  open  air,  and 
not  into  an  air  shaft.  The  closet  itself  should  be  along 
the  inner  wall,  opposite  a  window,  so  as  to  afford  plenty 
of  light  to  detect  any  defects. 

The  arrangement  of  a  bath-room,    in  which  all   the 


Fig.  36. — S-trap. 


Fig.  2)1  • — Bell-trap. 


Fig.  38. — Anti-D  trap. 

modern  improvements  in  the  sanitary  removal  of  sewage 
are  supplied,  is  shown  in  Fig.  35.  In  the  modern  dwell- 
ings now  being  constructed  the  conveniences  supplied  in 
bath-rooms  are  important  factors  in  conserving  the  health 
of  the  individual  as  well  as  of  the  community. 

Traps. — A  trap  is  a  bend  in  the  pipe  which  is  filled  with 
water  so  as  to  prevent  the  entrance  of  sewer  or  drain  aii 
into  the  house.     It  consists  of  a  water  seal  in  the  pipe. 


—^    . 


o 


\  '"^^ 


l'  !', 


SOIL  PIPE. 


DO 


All  appliances  on  the  drainage  pipes  of  a  house,  such  as 
water-closets,  sinks,  etc.,  must  be  supplied  with  a  trap. 
The  different  forms  of  traps  in  use  are  the  S-trap,  the 


Fig.  39. — Mason's  trap. 

bell-trap,  the  anti-D   trap,   and  Mason's  trap  (Figs.    2^6^ 
2,7,  38,  and  39). 

Soil  Pipe. — The  pipes  for  carrying  away  the  sewage 


Fig.  40. — Method  of  connecting  soil  pipe  with  house  drain. 

from  a  house  are  called  soil  pipes.  For  an  ordinary  dwell-' 
ing  the  soil  pipes  should  be  constructed  of  heavy  iron 
tubing,  with  tight  joints,  circular  in  shape,  and  10  centim- 
eters in  diameter.  The  interior  of  the  soil  pipe  must  be 
smooth,  so  as  not  to  impede  the  flow  of  the  sewage.  The 
soil  pipe  is  ventilated  through  the  warming  of  its  contained 
air,  causing  an  upward  current,   the  fresh  air  entering 


156   THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

through  a  ventilator  opening  on  the  outside  of  the  house 
next  the  point  of  disposal,  and  takes  its  exit  through  the 
upper  end  of  the  pipe,  which  is  carried  up  over  the  roof 
of  the  building.  The  soil  pipe  should  have  an  S-shaped 
trap  between  the  ventilator  opening  and  the  sewer.  All 
connections  of  drainage  pipes  with  the  soil  pipe  must  be 
absolutely  tight,  and  should  be  made  at  an  acute  angle, 
not  at  a  right  angle  with  the  soil  pipe  (Fig.  40). 

Where  several  closets  on  different  floors  discharge  into 


Jl 


^ 


^ 


^1=7 


Fig.  41. — Arrangement  of  soil  pipe. 

the  same  soil  pipe,  the  suction  of  the  water  in  the  soil 
pipe  causes  the  trap  of  the  other  closet  to  become  un- 
sealed. To  obviate  this  defect  the  traps  are  supplied 
with  a  separate  ventilating  pipe  of  small  diameter,  which 
enters  into  the  soil  pipe  above  the  highest  appliance  of 
the  system.  These  extra  pipes  also  serve  to  ventilate  the 
traps  and  pipes,  and  for  this  reason  this  is  frequently 
spoken  of  as  the  "back-airing"  of  traps.     It  serves  to 


DR  Y  ME  THOD  OF  SE  WA  GE  RE  MO  VAL.        157 

supply  fresh  air  to  the  pipes,  and  thus  serves  to  prevent 
the  growth  of  anaerobic  bacteria  in  the  unventilated  por- 
tion of  the  traps.  This  prevents  the  generation  of  dis- 
agreeable odors.  The  method  of  ventilation  of  soil  pipe 
and  the  traps  is  represented  in  Fig.  41. 

The  required  amount  of  fall  for  house  drains  may  be 
determined  according  to  the  following  rule:  Multiply  the 
diameter  of  the  drain  in  centimeters  by  4;  thus  a  10- 
centimeter  drain  should  have  a  fall  of  i  in  40;  a  15-centim- 
eter drain  i  in  60,  and  so  on.     If  the  distance  from  the 


'"  Fig.  42. — Dry-earth  closet. 

appliance  to  the  soil  pipe  is  too  great  to  obtain  the 
requisite  amount  of  fall  in  the  limited  space  between 
floor  and  ceiling,  it  will  be  necessary  to  have  extensions 
from  the  soil  pipe  from  the  basement  to  the  roof  to 
receive  these  drains. 

Another  method  of  sewage  removal  is  usually  spoken 
of  as  the  dry  method.  The  pail  system  and  the  dry- 
earth  closet  are  the  principal  types  of  the  dry  methods  of 
sewage  removal.  In  the  pail  system  the  excreta  are 
simply  received  in  boxes  or  tanks,  and  these  are  emptied 
whenever  necessary.     In  the  dry-earth  closet  a  receptacle 


158  THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

containing  dry  earth  is  placed  in  the  closet  and  about 
yi  kilogram  of  dry  earth  is  thrown  over  each  evacua- 
tion (Fig.  42).  The  earth  is  a  natural  deodorizer  and  the 
mass  remains  inoffensive  for  a  long  time,  the  fecal  matter 
being  finally  entirely  disintegrated.  A  separate  recepta- 
cle is  supplied  for  the  collection  of  the  urine.  This  sys- 
tem is  the  least  objectionable  in  such  localities  where  a 
general  water-supply  is  not  available,  or  where  the 
climate  is  too  severe  to  render  a  water-closet  safe  and 
serviceable. 

Disposal  of  Sewage. — The  question  of  the  disposal 
of  sewage  is  distinct  from  that  of  sewage  removal,  but 
the  method  of  disposal  is  dependent,  to  some  extent, 
upon  the  method  of  removal.  In  the  dry  methods  of 
removal  the  final  disposal  of  the  fecal  matter  is  as  fertil- 
izer upon  cultivated  land.  If  the  removal  is  by  means 
of  water,  this  will  be  either  partial,  as  to  a  cesspool,  and 
hence  further  removal,  after  longer  or  shorter  intervals, 
as  well  as  final  disposal,  may  be  necessary,  or  the  removal 
may  be  partial  through  a  sewerage  system  and  final  dis- 
posal into  streams  or  large  bodies  of  water,  treatment  by 
precipitation  processes,  or  by  the  various  methods  of 
purification. 

In  rural  districts  where  there  is  no  general  sewerage 
system  the  house  drains  usually  discharge  into  cesspools 
or  tanks  for  the  storage  of  sewage.  Cesspools  differ;  in 
their  construction  and  mode  of  operation  according  to 
the  nature  of  the  soil  in  which  they  are  located.  Where 
the  soil  permits  and  the  amount  of  space  is  sufficient, 
the  cesspool  may  be  constructed  so  as  to  allow  the  fluid 
portion  of  the  sewage  to  drain  away  at  once.  Where  no 
wells  are  near  enough  to  be  affected  by  this  process  the 
cesspool  may  operate  for  a  long  time  without  being 
cleaned  out.  Where  the  nature  of  the  soil  does  not 
permit  this  mode  of  disposal  of  the  fluid  portion  of  the 
sewage,  or  where  there  is  danger  of  infecting  neighbor- 
ing wells,  the  cesspool  should  be  so  constructed  as  to  be 
impervious.       Under    these   conditions    it   will    require 


DISPOSAL   OF  SEWAGE.  159 

frequent  cleansing,  the  contents  removed  serving  as 
fertilizer.  Such  a  cesspool  should  be  removed  from  the 
house  and  well  as  far  as  possible,  and  in  such  a  position 
that  the  flow  of  the  ground  water  is  always  in  the  direc- 
tion from  the  well  toward  the  cesspool. 

A  large  majority  of  towns  discharge  their  sewage  into 
neighboring  streams.  All  new  works  of  this  nature  are 
prohibited  in  Bngland.  In  Ohio  and  Pennsylvania 
health  authorities  also  have  the  power  to  prohibit  new 
works  of  this  nature  wherever  the  stream  serves  as  a 
source  of  water-supply  for  another  town  further  down  its 
course.  The  effect  of  discharging  sewage  into  streams  is 
such  that  the  streams  are  polluted  to  an  extent  sufiicient 
to  destroy  the  fish  contained  in  it.  Such  water  is  always 
injurious  to  health  when  used  for  drinking-purposes. 
The  Rivers'  Pollution  Commission  of  England  reached 
the  conclusion  that  none  of  the  rivers  of  England  were 
long  enough  to  purify  themselves  by  the  natural  agencies 
after  having  been  polluted. 

Towns  along  the  seaboard  find  the  easiest  and  most 
economical  method  of  sewage  disposal  is  to  discharge  it 
into  the  sea.  There  are,  however,  objections  to  this 
method.  If  the  discharge  is  made  near  a  watering-place, 
it  will  injure  the  bathing.  The  sea-water  will  also  cause 
the  precipitation  of  certain  constituents  of  the  sewage, 
and  this  matter  will  cause  the  formation  of  a  barrier  or 
reef  along  the  shore,  unless  it  is  carried  out  into  deep 
water. 

As  an  indication  of  the  methods  of  sewage  purification 
employed  to-day  the  following  data  are  given,  showing 
the  practice  in  various  parts  of  the  State  of  Ohio.'  From 
1893  to  1912  inclusive  46  municipal  purification  plants 
have  been  constructed  and  32  plants  for  institutions. 
The  population  served  by  the  municipal  plants  is  456,600 
and  by  the  institutional  plants  16,900.  The  methods 
employed  for  municipalities  are:  Sedimentation,  4;  sedi- 
mentation  and   disinfection,!;  sedimentation  and  inter- 

^Dittoe:  Monthly  Bulletin,  Ohio  State  Board  of  Health,  vol.  cxi.,  1913. 


i6o    THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

mittent  sand  filtration,  19;  sedimentation  and  sprinkling' 
filters,  2;  preliminary  sedimentation,  sprinkling  filters,  and 
final  sedimentation,  2;  sedimentation  and  single  contact 
filters,  10;  sedimentation,  contact  and  intermittent  sand 
filtration,  6;  natural  land  filtration,  i;  sedimentation  and 
coarse  grain  filters,  i.  For  the  year  191 3  there  were  in 
contemplation  18  additional  purification  plants  to  serve  a 
population  of  196,400.  These  new  plants  are  of  the 
following  types:  Sedimentation  and  intermittent  sand 
filtration,  6;  sedimentation  and  contact  filters,  i;  two-story 
tanks,  primary  and  secondary  contact  filters,  2 ;  two-story 
tanks,  contact  filters  and  intermittent  sand  filters,  i;  two- 
story  tanks  and  simple  contact  filters,  6. 

Dittoe  states  that  the  fundamental  consideration  to  be 
given  in  determining  upon  the  required  degree  of  treat- 
ment of  sewage  to  avoid  nuisance  is  the  dilution 
afforded  by  the  volume  of  the  flow  of  the  stream.  One 
of  the  most  important  difficulties  encountered  in  prevent- 
ing stream  pollution  is  the  failure  to  secure  proper 
operation  of  the  sewage  treatment  plants  after  they  are 
installed,  and  has  led  to  the  adoption  of  the  simpler 
methods,  wherever  possible,  instead  of  the  more  refined 
methods,  which  require  more  careful  management. 

Chemical  Treatment  of  Sewage. — Where  there  is 
removal  by  water,  but  no  opportunity  for  disposal  into 
streams  or  other  bodies  of  water,  the  sewage  may 
be  subjected  to  one  of  several  processes  of  precipita- 
tion. The  sewage  is  sometimes  first  strained  to  re- 
move the  coarser  particles  by  passing  it  through  screens. 
The  materials  employed  in  precipitation  processes  are 
lime  and  ammonium  sulphate;  lime  and  iron  protosul- 
phate;  the  ABC  mixture,  consisting  of  alum,  blood,  and 
clay;  and  ferrozone  and  polarite.  The  precipitated 
matter,  or  sludge,  as  it  is  called,  is  used  for  fertilizing 
purposes,  and  the  fluid  portion  is  discharged  into 
streams. 

Precipitation  works  are  in  use  in  the  following  cities 
of  England  :  Acton,  Ealing,  and  Sutton,  and  the  process 


CHEMICAL   TREATMENT  OF  SEWAGE.        i6i 

is  still  partially  in  use  at  Manchester,  though  here  a 
portion  of  the  sewage  is  treated  by  several  of  the  modern 
methods  of  purification.  Precipitation  works  are  also 
in  use  at  Frankfort-on-the-Main,  at  Alliance,  O.,  and  at 
Worcester,  Mass.,  though  at  the  latter  place  a  portion  of 
the  sewage  is  purified  by  filtration. 

The  various  methods  of  chemical  treatment  of  sewage 
may  be  divided  into  the  following  groups  : 

1.  Intermittent  treatment  in  tanks  from  1.5  to  2.5 
meters  deep,  in  which,  after  the  addition  and  incorpora- 
tion of  the  chemicals,  the  sewage  is  allowed  to  remain 
until  the  completion  of  the  process. 

2.  Continuous  treatment  in  a  series  of  tanks  through 
which,  after  the  addition  and  incorporation  of  the  chem- 
icals, the  sewage  flows  slowly;  crude  sewage  and  chem- 
icals passing  in  at  one  end,  and  purified  efiiuent  passing 
out  at  the  other. 

3.  Vertical  tanks  through  which  the  sewage  rises 
slowly  after  the  addition  of  the  chemicals. 

There  are  a  number  of  variations  of  these  three  sys- 
tems, but  none  of  them  is  important  enough  to  justify 
further  subdivision  into  classes. 

The  conditions  necessary  for  success  from  chemical 
treatment  are  as  follows  : 

1.  The  sewage  should  be  treated  while  fresh. 

2.  The  chemicals  should  be  added  to  the  flowingf 
sewage  and  thoroughly  mixed  with  it  before  it  passes 
into  the  settling  tanks. 

3.  There  should  be  a  liberal  amount  of  tank  space. 

4.  The  arrangements  for  the  removal  of  the  sludge 
should  be  such  as  to  insure  its  frequent  removal. 

The  sludge  obtained  by  the  treatment  of  sewage  is 
often  a  further  trouble,  because  it  has  to  be  finally  dis- 
posed of.  It  may  be  burned,  or  it  may  be  used  for 
fertilizer  if  it  can  be  disposed  of  in  this  manner.  At 
Manchester,  England,  much  of  the  sludge  has  been 
used  in  filling  in  low  land  adjacent  to  the  precipitation 
works. 
11 


1 62    THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

Modem  Methods   of  Sewage   Purification. —  The 

old  theory  that  filth  containing  pathogenic  organisms 
would,  when  exposed  to  the  sun,  propagate  various  dis- 
eases, has  been  entirely  overthrown.  Experimentally 
and  practically,  sewage  has  been  discharged  upon  land, 
which  may  or  may  not  have  been  prepared  to  receive  it, 
with  the  result  that  the  pathogenic  organisms  and  the 
offensive  nature  of  the  material  are  most  effectively 
destroyed. 

If  the  sewage  is  discharged  onto  a  piece  of  land  for 
the  purpose  of  enriching  the  soil  for  raising  crops,  it  is 
known  as  irrigation ;  if  it  is  discharged  over  a  large  area, 
it  is  called  broad  irrigation;  if  it  is  discharged  upon  land 
specially  prepared  to  receive  it,  with  no  idea  of  raising 
crops,  it  is  known  as  filtration. 

In  broad  irrigation  the  fields  should  be  divided  into 
sections  lo  to  15  meters  square,  which  are  raised  in  the 
middle;  or  if  the  fields  are  uneven  in  contour,  they 
should  be  raised  into  ridges  of  corresponding  width. 
The  sewage  is  conveyed  to  the  middle  of  the  section 
through  an  open  drain.  At  certain  distances  dykes  are 
placed  in  a  drain,  which  cause  the  sewage  to  overflow  on 
the  slopes  of  the  section.  In  order  to  operate  satisfac- 
torily, and  carry  the  sewage  to  all  parts  of  the  field,  it  is 
discharged  upon  the  field  intermittently,  either  auto- 
matically by  means  of  a  Field  flushing  tank  (Fig.  43) 
or  by  opening  and  closing  sluices  whenever  a  discharge  is 
desired.  In  cold  latitudes  the  operation  of  the  irrigation 
field  is  inhibited  by  frost,  as  the  absorptive  power  of  the 
soil  is  feeble  at  low  temperatures.  From  a  sanitary 
standpoint  the  system  has  had  a  most  careful  investiga- 
tion, especially  in  England,  and  these  observations  have 
failed  to  show  the  origin  of  any  case  of  contagious  dis- 
ease from  it. 

Since  1870,  when  the  Rivers'  Pollution  Commission  of 
England  proposed  in  their  report  the  purification  of 
sewage  by  irrigation  of  cultivated  land,  the  system  has 
been  introduced  into  over    145    English  towns.     Other 


MODERN  ME  THODS  OF  SE  WA  GE  PUR  I  PICA  TION.   1 63 

European  towns  have  also  adopted  it,  including  Berlin, 
Breslau,  and  Dantzig.  In  America  it  has  been  introduced 
at  Wayne,  Pa.,  Pullman,  111.,  Greenfield,  Mass.,  and 
Berlin,  Out.  In  the  western  States,  where  there  is  a 
scarcity  of  water,  sewage  has  been  utilized  for  irrigation 
with  considerable  success.  In  California,  Fresno,  Pasa- 
dena, Redding,  Los  Angeles,  Santa  Rosa,  and  Stockton, 
all  irrigate  with  sewage.  In  Colorado,  Colorado  Springs 
and    Trinidad    utilize   sewage   for    irrigation    purposes. 


=::3 


Fig.  43. — Field's  flushing  tank. 


Helena,  Mont.,  and  Cheyenne,  Wyo.,  also  utilize  sewage 
in  this  manner. 

In  order  to  operate  satisfactorily  the  system  requires  i 
acre  of  area  for  each  2000  persons  (2  square  meters  per 
person),  and  consequently  it  is  not  adapted  for  localities 
where  cheap  land  in  sufficient  quantities  and  of  suitable 
quality  cannot  be  obtained.  Large  towns  must,  there- 
fore, usually  avail  themselves  of  some  other  method  of 
sewage  purification. 

Purification  by  Filtration  Tlirough  5and. — The  filtra- 
tion of  sewage  through  specially  constructed  sand  filters, 
or  through  a  natural  sandy,  loamy  soil,  is  efficacious 
in  the  purification  of  sewage.  Because  of  the  absence  of 
free  oxygen  in  sewage  the  filtration  must  be  carried  on 
by  the  intermittent  method  in  order  to  give  the  nitrify- 
ing bacteria  an  opportunity  to  recuperate.     These  filters 


l64  THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

are  usually  operated  for  half  a  day  and  then  allowed  to 
rest  the  second  half  of  the  day.  This  necessitates  the 
construction  of  two  filters  that  can  be  operated  alter- 
nately. 

Experimentally,  much  work  has  been  done  at  the 
Lawrence,  Mass.,  Experiment  Station  upon  intermittent 
filtration,  by  passing  sewage  through  various  depths  of 
different  soils.  It  was  found,  among  other  results,  that 
some  forms  of  bacteria  would  pass  through  certain  filters 
more  readily  than  others;  that  in  certain  cases  where  the 
total  number  of  sewage  bacteria  had  increased  while 
the  sewage  was  passing  through  the  filter,  the  number 
of  species  of  bacteria  had  greatly  diminished. 

Intermittent  filtration  has  been  in  practical  operation 
for  some  time  at  Chichester  and  Sutton,  England,  and  at 
Gardner,  Marlborough,  Clinton,  South  Framingham, 
Medfield,  Worcester,  and  Brockton,  Mass.,  Summit, 
N.  J.,  East  Cleveland,  O.,  Hastings,  Neb.,  Vassar 
College,  Poughkeepsie,  N.  Y.,  and  the  Iowa  State 
College,  at  Ames,  also  recently  adopted  this  system 
of  purification.  In  all  of  these  towns  the  system  em- 
ployed is  practically  a  combination  of  filtration  and 
irrigation.  The  effluent  water  from  this  combined  filtra- 
tion and  irrigation  method  in  no  way  indicates  its  origin 
by  temperature  or  smell.  It  may  easily  be  mistaken  for 
spring-water,  as  it  comes  out  of  the  pipe  clear  and 
sparkling. 

At  Amherst,  Mass. ,  the  sewage  is  collected  in  a  stone 
tank  450  X  600  X  180  centimeters  in  size,  divided  into  two 
equal  compartments,  in  which  the  sewage  is  allowed  to 
settle.  This  arrangement  allows  one  compartment  to  be 
cleaned  of  its  sludge  while  the  other  is  receiving  the 
sewage.  The  sludge  is  removed  once  a  week.  The 
effluent  flows  through  a  pipe  to  the  river,  about  150 
meters  distant.  No  further  purification  of  the  sewage  is 
attempted.  This  method  is  obviously  incomplete,  and 
should  be  used  only  as  a  preliminary  step  to  irrigation, 
filtration,  or  chemical  treatment. 


MODERN  METHODS  OF*SE  WAGE  PURIFICA  T/ON.  165 

The  following  table  shows  the  average  results  of  con- 
tinuous filtration  through  io|  feet  of  coarse  broken 
stone,  at  an  average  rate  of  1,897,000  gallons  per  acre 
daily  for  six  days  in  the  week,  from  May  to  November, 
inclusive  (parts  per  100,000): 

Filtration  through   Coarse  Broken   Stone. 

Sewage.  Effluent. 

Temperature,  degrees  Fahr 63  63 

Free  ammonia 3.47  0.7265 

Albuminoid  ammonia 0.57  0.0963 

Chlorin 7.58  5.96 

Nitrogen  as  nitrates — ■ —  1.88 

Nitrogen  as  nitrites O.I 247 

Oxygen  consumed 3.72  1. 09 

Bacteria  per  c.c 2,049,000  144,000 

Dissolved  oxygen,  percentage  of  satura- 
tion             3S 

Subsurface  Irrigation, — Another  method  of  sewage 
disposal  which  is  available  for  small  towns  or  for  isolated 
dwellings  or  hotels  in  rural  districts,  is  what  is  known  as 
subsurface  irrigation.  In  this  system  pipes  with  open 
joints  are  distributed  underneath  the  garden  or  lawn 
through  which  the  sewage  flows  and  percolates  through 
the  open  joints  into  the  soil.  This  system  requires  the 
introduction  of  a  flushing  tank  in  order  to  carry  the 
sewage  to  all  parts  of  the  system.  The  household  drains 
empty  into  a  large  flushing  tank,  having  a  capacity  of 
about  15  cubic  meters,  separated  into  two  chambers  by  a 
wire-cloth  strainer  to  hold  back  obstructing  material.  A 
certain  amount  of  sludge  accumulates  in  the  bottom  of 
the  tank  and  has  to  be  removed  at  intervals.  This  sys- 
tem requires  about  40  square  meters  of  area  for  each  per- 
son (i  acre  per  100  persons). 

Sludge  Digestion. — The  heavier  portions  of  sewage 
which  settle  on  standing  give  the  most  trouble  in  sewage 
purification.  A  number  of  methods  have  been  devised 
to  accomplish  the  disintegration  of  the  sludge. 

It  has  been  found  that  the  methods  in  which  the  sludge 
is  exposed  to  the  action  of  the  anaerobic  bacteria  give  the 
most  satisfactory  results.    Of  the  sludge  digestion  tanks, 


l66  THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

those  which  are  in  common  use  to-day  are  the  so-called 
septic  tank  of  Cameron  and  the  Emscher  tank. 

Activated  Sludge. — The  accumulation  of  sludge  in  the 
different  processes  employed  in  sewage  purification  has 
been  a  feature  that  has  now  become  less  troublesome  in 
what  is  known  as  the  "activated  sludge"  digestion  proc- 
ess. This  consists  in  providing  for  the  continuous  aera- 
tion of  the  sewage  as  it  passes  through  the  digestion 
tank.  The  rate  of  nitrification  of  the  organic  constitu- 
ents of  the  sewage  is  greatly  enhanced  in  this  process. 

The  Cameron  Septic  Tank. — Within  recent  years  the 
purification  of  sewage  on  a  large  scale  has  been  studied  ex- 
perimentally and  practically  in  what  is  known  as  the  sep- 
tic tank  or  bacterial  treatment  of  sewage  (Figs.  44,  45). 
This  system  utilizes  the  dissolving  and  liquefying  ac- 
tion of  anaerobic  species  of  bacteria  in  one  portion,  the 


Fig.  44. — Arrangement  of  septic  tank  and  series  of  filter  bed^. 

so-called  septic  tank,  and  the  oxidizing  action  of  aerobic 
species  of  bacteria  in  another  portion,  the  filter  beds, 
several  of  which  are  arranged  in  series.  Various  modifi- 
cations of  the  system  are  in  use  in  England  and  America, 
all  being  on  the  general  plans  proposed  by  Cameron. 
The  sewage  is  discharged  into  settling  basins,  from  which 
it  is  transferred  to  the  septic  tank.  In  some  of  the  works 
the   septic   tank    is    made  practically    air-tight,   so  as  to 


MODERN  METHODS  OF  SE  WAGE  PURIFICA  TION.  167 


facilitate  the  growth  of  anaerobic  species.  In  others  it  is 
simply  an  open  tank,  the  idea  being  that  since  the  sewage 
is  devoid  oi  free  oxygen,  therefore  the  conditions  are 
favorable  to  the  development  of  the  anaerobic  species, 
because  the  surface  scum  which  forms  renders  the  access 
of  air  without  effect.  Some  of  the  action  which  it  is 
proposed  to  obtain  in  the  septic 
tank  has  already  taken  place  in 
the  sewage  during  its  course  to 
the  disposal  works.  The  flow  of 
the  sewage  through  the  tank  is 
regulated  so  that  the  solid  matter 
may  undergo  solution  and  lique- 
faction, and  is  then  discharged 
upon  the  first  series  of  four  or  five 
filters,  on  which  a  mixed  action 
of  anaerobic  and  aerobic  bacteria 
takes  place,  bringing  about  the  ^ 
breaking  down  of  the  intermedi- 
ate dissolved  bodies.  These  fil- 
ters are  operated  automatically, 
so  that  one  fills  after  the  other. 
When  the  last  filter  begins  to  fill, 
the  first  filter  discharges  its  con- 
tents. From  these  primary  filters 
the  sewage  is  discharged  on  to 
another  set  of  filters,  the  second- 
ary or  aerobic  filters,  where  the 
oxidation  process  is  completed. 
In  some  of  the  works  the  sewage 
is  discharged  on  to  the  secondary 
beds  by  means  of  a  revolving 
sprinkler.  Some  of  the  works 
are  without  the  secondary  filter 
beds.  The  filter  beds  are  com- 
posed of  various  kinds  of  mate- 
rial, as  clinkers  and  coke. 

The  Emscher  Tank. — The    Emscher   tank    consists    of 
two  cvlinders,  one  smaller  than  the  other,  and  placed  in- 


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i68  THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 


Influent 


'Influehh 


side  the  larger  cylinder.  The  bottom  of  the  larger  cylin- 
der is  conical  in  shape,  and  the  sludge  is  collected 
at  the  bottom  of  the  tank,  where  it  is  protected  from  the 
stream  of  sewage  which  is  passing  through  the  tank 
(Fig.  45«).  The  gases  which  are  formed  by  the  action 
of  the  anaerobic  bacteria  on  the  organic  matter  in  the 

sewage  pass  up  through  the 
smaller,,  inner  cylinder,  and 
escape  into  the  air.  This 
prevents  them  from  coming 
in  contact  with  the  sewage 
flowing  through  the  tank. 

Sprinkling  Filters. — 
Sprinkling  filters  are  the 
outcome  of  experiments 
with  gravel  filters  at  the 
Lawrence  Experiment  Sta- 
tion,^  but  the  experiments 
of  Mr.  Joseph  Corbett,  bor- 
ough engineer  of  Salford, 
England,  have  brought  this 
method  of  sewage  purifica- 
tion into  prominence  in 
England.  The  filters  are 
constructed  of  five  feet  of 
crushed  stone  resting  on  six 
inches  of  gravel,  that  is, 
gravel  underdrains.  The  crushed  stone  employed  varies 
in  size  from  0.25  to  2  inches  in  diameter. 

The  sewage  is  applied  intermittently  to  the  surface  of 
the  filter  in  the  form  of  a  spray.  This  gives  opportunity 
for  the  sewage  to  become  aerated.  Satisfactory  results 
are  obtained  when  the  sewage  contains  about  80  per  cent, 
of  the  amount  of  air  required  to  saturate  it.  Sewage 
may  be  applied  to  filters  of  this  character  at  the  rate  of 
5,000,000  gallons  per  acre  per  day  and  obtain  an  effluent 
that  is  not  putrescible.  The  effluent  will  contain  only 
about  10  per  cent,  of  the  applied  bacteria,  and  will  show 

1  Special  Report  Mass.  State  Board  of  Health,  1890,  part  2,  pp.  549  and  565. 


Fig.  45  «. — Emscher  tank. 


SPRINKUNG  FIL  TERS.  169 

a  reduction  of  the  organic  matter  and  its  conversion  into 
nitrates  and  nitrites  through  the  agency  of  the  nitrifying 
bacteria. 

During  1904-05  Mr.  George  A.  Johnson  conducted 
extensive  investigations  upon  the  serviceability  of  differ- 
ent modern  methods  of  sewage  purification  at  Columbus, 
Ohio.  The  methods  of  purification  tested  in  these  investi- 
gations were :  sedimentation,  precipitation,  septic  tank, 
filtration  through  sand  filters,  contact  filters,  and  sprink- 
ling filters. 

The  process  which  was  recommended  to  the  city  of 
Columbus  as  being  the  most  satisfactory  is  that  of  the 
sprinkling  filters,  preceded  by  the  preliminary  clarification 
of  the  sewage  in  settling  basins : 

"  I.  Preliminary  clarification  of  the  sewage  in  basins 
holding  on  an  average  about  an  eight-hour  flow  and  oper- 
ated on  the  basis  of  the  septic  treatment. 

"  2.  Purification  of  the  septic  efiluent  to  a  non-putres- 
cible  state  by  sprinkling  filters  at  an  average  rate  of 
2,000,000  gallons  per  acre  daily. 

"  3.  Final  clarification  of  the  efiluent  of  the  sprinkling 
filters  in  basins  holding  an  average  flow  of  about  two 
hours. ' ' 

At  the  Sewage  Experiment  Station  in  Philadelphia 
the  efliciency  of  the  sprinkling  filter  in  the  purification 
of  sewage  was  studied  in  detail.  With  filters  exposed  to 
the  weather  and  receiving  sewage  "partially  settled  "  the 
maximum  rate  obtained  was  250,000,000  gallons  per  acre 
per  day.  With  a  filter  protected  from  the  weather  a  rate 
of  three  and  one-tenth  million  gallons  was  used.  The 
filters  were  constructed  of  trap-rock,  one  to  three  inches 
in  size,  in  beds  ranging  from  six  to  nine  feet  in  depth. 
The  bacterial  efliciency  of  the  sprinkling  filters,  when 
operated  at  a  rate  between  2,500,000  and  3,000,000  gal- 
lons per  acre  per  day,  was  400,000  per  c.c. ,  representing 
a  reduction  of  86  per  ceut. 

The  degree  of  purification,  which  it  is  aimed  to  secure 
in  the  modern  systems  of  sewage  purification,  is  such  that 
the  efiluent  shall  not  be  putrescible  and  give  rise  to  no 


lyo    THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

perceptible  pollution  of  the  body  of  water  into  which  the 
effluent  is  allowed  to  flow.  The  amount  of  reduction  of 
the  organic  matter  in  the  sewage  may  vary  in  the  effluent 
of  different  systems,  depending  upon  the  extent  to  which 
it  is  diluted  by  the  body  of  water  into  which  it  is  dis- 
charged and  the  use  of  such  water  at  points  near  by.  As 
the  sprinkling-filter  effluent  contains  large  numbers  of 
the  sewage  bacteria,  it  is  at  times  advisable  to  treat  this 
effluent  with  hypochlorites  in  order  to  disinfect  it. 

Since  1859  ^^^  city  of  Birmingham,  England,  has  been 
studying  in  a  practical  way  various  methods  of  sewage 
purification,  beginning  with  sedimentation,  chemical  pre- 
cipitation, filtration,  septic  tank  treatment,  and  finally 
purification  by  means  of  sprinkling  filters.  They  have 
found  that  the  latter  method  is  far  cheaper  and  more  sat- 
isfactory than  any  other  method  heretofore  employed,  and 
they  are  now  displacing  all  other  methods  for  the  sprink- 
ling filters. 

Removal  of  Sewage  by  I^iernur  System. — The 
satisfactory  disposal  of  sewage  is  influenced  directly 
by  the  fact  whether  the  removal  is  by  the  separate  or 
combined  system.  In  the  separate  system  of  removal 
two  sets  of  pipes  are  provided,  one  set  for  the  house- 
hold sewage,  and  another  for  the  storm-water.  This  sim- 
plifies the  purification  process  to  a  considerable  extent. 
When  the  separate  system  of  removal  is  employed  some 
provision  must  be  made  for  either  flushing  out  the  pipes 
carrying  the  household  sewage,  such  as  a  flushing  tank 
at  the  head  of  each  branch  sewer,  or  one  of  the  methods 
of  ' '  air  removal ' '  may  be  employed.  The  method  of 
air  removal  in  more  common  use  is  what  is  known  as  the 
Liernur  system.  In  this  system  there  are  two  sets  of 
pipes,  the  one  set  containing  air  only,  and  by  the  produc- 
tion of  a  partial  vacuum  in  this  set  of  pipes  the  sewage  is 
extracted  from  the  drain  pipes.  The  system  is  so  arranged 
that  the  discharges  from  each  house  are  delivered  into  an 
air-tight  metal  reservoir,  from  which  they  are  in  turn 
drawn  by  suction  into  larger  collecting  tanks,  these  lat- 


COMMERCIAL   VALUE   OF  SEWAGE.  171 

ter  delivering  the  matter  into  a  stream  or  into  the  dis- 
posal works.  The  main  collecting  tanks,  receiving  the 
sewage  from  the  different  branches,  are  at  the  lowest 
point  of  the  district  drained.  A  powerful  suction  pump 
produces  a  vacuum  in  the  system,  and  once  a  day  the 
entire  system  is  exhausted.  Each  branch  drain  and 
reservoir  is  extracted  in  turn  by  closing  off  the  rest  of  the 
system  by  means  of  valves;  and  finally  the  main  collect- 
ing tanks  are  extracted.  The  entire  operation  is  the 
work  of  one  man,  who  makes  the  tour  of  the  system,  his 
only  labor  being  the  opening  and  closing  of  valves. 
There  is  nothing  to  give  offence  to  the  senses  in  this  sys- 
tem, as  all  the  tanks  are  underground  and  the  valves  are 
operated  from  connections  at  the  surface  of  the  ground. 
Owing  to  the  manner  in  which  the  material  is  collected, 
its  conversion  into  fertilizer  is  commercially  possible,  so 
as  to  yield  a  considerable  revenue.  At  Trouville, 
France,  where  the  population  during  the  season  reaches 
20,000,  it  is  estimated  that  the  receipts  from  the  sale  of 
the  poudrette  will  furnish  a  material  income  over  and 
above  the  operating  expenses.  This  system  of  air  ex- 
traction is  especially  adapted  for  places  in  which  the 
sewers  lie  too  low  to  discharge  directly  into  streams. 

The  Liernur  system  of  extraction  has  been  in  opera- 
tion for  more  than  twenty-five  years  in  Amsterdam  and 
Leyden,  and  its  success  in  these  older  installations  has 
led  to  its  introduction  into  other  cities.  The  latest  appli- 
cation of  the  method  has  recently  been  completed  at  the 
watering-place  Trouville,  France. 

Commercial  Value  of  Sewage. —  Many  scientists 
have  attempted,  by  chemical  analysis,  to  demonstrate 
the  commercial  value  of  the  constituents  of  sewage  as 
fertilizer.  One  investigator  has  estimated  the  yearly 
solid  and  liquid  excreta  of  an  adult  person  to  yield  7.44 
kilograms,  an  amount  sufficient  to  fertilize  about  365 
kilograms  of  wheat,  rye,  or  oats,  or  about  410  kilograms 
of  barley ;  equivalent  to  34  kilograms  of  Peruvian 
guana.      Several  scientists  have  estimated  the  manurial 


172     THE  REMOVAL  AND  DISPOSAL  OF  SEWAGE. 

value  of  London  sewage  to  range  from  3)^  to  5  cents  per 
ton,  having  an  annual  value  of  14,000,000  to  20,000,000 
dollars.  It  does  not  matter,  however,  what  the  intrinsic 
value  may  be  of  the  manurial  constituents  of  sewage,  the 
nitrogen,  phosphoric  acid,  and  potash  salts,  so  long  as 
the  conditions  affecting  supply  and  demand  can  neither 
be  controlled  nor  regulated,  its  commercial  value  must 
remain  very  small — indeed,  so  small  that  sewage  is  much 
more  likely  to  become  a  source  of  expense  than  one  of 
revenue  to  any  community.  This  has  been  the  expe- 
rience almost  everywhere  where  attempts  have  been 
made  to  utilize  sewage  as  fertilizer.  The  compressed 
sludge,  the  product  of  precipitation  works,  accumulates 
far  more  rapidly  than  it  can  be  disposed  of  as  fertilizer, 
and  it  frequently  becomes  a  troublesome  matter  to  dis- 
pose of  it  economically  and  satisfactorily.  Even  in  such 
instances  where  sewage  is  utilized  to  irrigate  cultivated 
fields  it  has  at  times  been  found  detrimental  to  the  crops 
raised,  principally  on  account  of  the  excessive  quantities 
applied  keeping  the  land  constantly  in  a  water-logged 
condition.  This  is  said  to  have  been  the  experience  at 
Pullman,  111. 


CHAPTER    VI. 
GARBAGE  DISPOSAL. 

The  whole  subject  of  the  disposal  of  garbage  and  other 
household  waste  must  be  considered  from  an  economic  as 
well  as  from  a  sanitary  standpoint,  if  satisfactory  results 
are  to  be  obtained.  The  question  of  utilization  has  here- 
tofore been  one  of  secondary  consideration.  If  the  cost 
of  disposal  can  be  reduced  by  utilizing  a  part  or  the  whole 
of  the  refuse,  then,  for  financial  reasons,  such  utilization 
should  be  advocated. 

The  sanitary  question  seems  to  narrow  itself  down 
mainly  to  the  prevention  of  all  nuisance,  no  evidence 
having  been  obtained  to  indicate  a  serious  effect  upon  the 
health  of  those  engaged  in  the  disposal  of  this  refuse  or 
in  picking  it  over  before  final  disposal. 

In  the  southern  States  the  term  ' '  garbage  ' '  is  some- 
times applied  to  dry  refuse  (Atlanta,  Ga.),  and  to  a 
mixture  of  dry  refuse  with  animal  and  vegetable  waste. 
In  New  England  the  word  "swill"  is  more  commonly 
used  to  designate  kitchen  waste,  etc.,  while  in  Pennsyl- 
vania and  one  or  two  other  States  "slop"  is  the  name 
applied  to  this  material.  The  garbage  is  usually  collected 
two  or  three  times  a  week,  but  somewhat  more  fre- 
quently in  densely  populated  districts,  and  during  the  hot 
weather  daily  collections  should  be  made  in  cities. 
Ashes  and  dry  refuse  are  usually  collected  once  a  week 
throughout  the  year.  The  collection  is  made  either  by 
private  service,  by  contract,  or  by  department  employes. 

The  best  information  obtainable  from  analyses  of  gar- 
bage made  in  Europe  shows  the  presence  of  60  to  80  per 
cent,  of  moisture;  rubbish,  such  as  bottles,  cans,  rags,  etc., 
about  7  per  cent. ;  animal  and  vegetable  dry  matter,  about 
20  per  cent. ;  and  grease,  from  2  to  4  per  cent.     The  ashes 

173 


174  GARBAGE  DISPOSAL. 

from  the  cremation  of  garbage  constitute  about  5  per  cent, 
of  the  original  mass.  Mr.  Westinghouse,  of  New  York, 
estimates  that  garbage  is  composed  of  about  20  per  cent, 
of  carbon  and  80  per  cent,  of  water. 

Collection  and  Removal  of  Garbage. — Where  the 
garbage  is  removed  either  by  the  municipal  authorities 
directly  or  by  contractors,  it  should  be  collected  in  water- 
tight receptacles  supplied  with  lids,  so  as  to  prevent  pol- 
lution of  the  air  and  soil  at  the  point  of  collection.  These 
receptacles  should  be  emptied  daily  during  the  summer 
months,  and  every  other  day  during  the  remainder  of  the 
year. 

The  carts  or  wagons  employed  in  removing  garbage 
should  be  constructed  of  metal,  and  so  designed  as  to  suit 
the  special  conditions.  These  carts  should  be  supplied 
with  lids,  so  that  none  of  the  material  may  be  lost  during 
removal,  and  also  to  limit  the  escape  of  objectionable 
odors  during  transit. 

The  following  form  of  ordinance,  recently  transmitted 
to  councils  by  the  mayor  of  Philadelphia,  is  intended  to 
reform  the  mode  of  handling  garbage,  the  reforms  being 
based  upon  the  regulations  in  force  in  New  York  and 
Boston : 

"Section  i.  That  it  shall  be  unlawful  for  any  person 
or  persons  to  keep  in  his  house  or  on  his  land  any  kitchen 
garbage  or  offal,  unless  the  same  is  placed  in  water-tight 
vessels,  free  from  ashes  and  other  refuse  matter  (except 
food  cans  and  food  bottles). 

"  Section  2.  No  person  shall  place  or  keep  in  or  near 
any  building,  ashes  or  cinders  in  such  a  manner  as  to 
cause  fire,  nor  mix  them  with  other  substances,  nor  place 
or  keep  them  except  in  metallic  vessels  so  placed  as  to  be 
easily  removed. 

"  Section  3.  All  other  refuse,  such  as  paper,  rags,  ex- 
celsior, straw  mattress,  old  clothing,  pasteboard  boxes, 
carpet,  and  other  household  waste,  shall  be  kept  in  suit- 
able vessels  free  from  ashes  and  garbage,  or  in  bundles, 
firmly  fastened  so  as  to  prevent  the  rubbish  from  being 


COLLECTION  AND  REMOVAL  OF  GARBAGE.    175 

scattered  in  the  handling,  and  protected  from  the  weather 
until  collected  by  the  proper  authority. 

' '  Section  4.  Ashes  placed  out  for  removal  shall  be 
moistened  sufficiently  to  keep  down  dust  while  handling, 
and  placed  within  4  feet  of  the  building-line,  in  vessels 
that  will  hold  their  contents  without  spilling;  shall  be 
placed  out  only  on  the  day  set  for  such  removal,  and 
taken  in  when  emptied  of  their  contents." 

Disposal  of  Garbage. — There  are  a  number  of  meth- 
ods of  disposal  in  use.  This  is  partly  due  to  the  varying 
character  of  the  refuse  in  different  cities,  as  regards 
moisture,  ashes,  unburnt  coal,  and  animal  and  vege- 
table matter,  and  partly  to  special  circumstances  which 
favor  one  or  the  other  method.  The  system  of  dispos- 
ing of  garbage  by  reduction  is  used  in  about  twelve 
cities  in  the  United  States.  Cremation  systems,  by 
which  garbage  is  destroyed  by  fire,  are  in  use  in  a 
large  number  of  cities.  Eight  cities  dispose  of  their 
garbage  by  dumping  it  on  land.  This  form  of  dis- 
posal costs  from  11  to  39  cents  per  capita  per  year. 
In  those  cities  which  dump  their  garbage  into  the 
sea  or  into  rivers  the  cost  is  from  36  to  75  cents  per 
capita.  In  cities  where  the  garbage  is  fed  to  animals  the 
cost  of  collection  and  disposal  varies  from  28  to  37  cents 
per  capita,  and  this  probably  takes  into  account  the  reve- 
nue which  the  contractor  derives  from  the  sale  of  this 
material.  In  smaller  cities  the  cost  of  disposal  by  feeding 
to  animals  is  sometimes  as  low  as  9  cents  per  capita. 
The  cost  of  disposal  by  reduction  processes  varies  from  15 
to  6^]  cents  per  capita.  The  cost  of  disposal  by  cremation 
is  found  to  vary  from  6  to  10  cents  per  capita  in  medium- 
sized  cities,  and  in  one  small  city  a  cost  of  20  cents  per 
capita  is  given. 

Several  years  ago.  New  York  City  made  a  contract 
with  the  New  York  Sanitary  Utilization  Company  for 
the  disposal  of  garbage,  the  price  being  about  $90,000 
per  annum.  It  contemplates  the  treating  of  the  garbage 
of  the  entire  city  by  steam,  sterilizing  it,  and  then,  by 


176  GARBAGE  DISPOSAL. 

great  pressure,  separating  the  water  and  grease  from  the 
residue  (called  "  tankage  "),  which  is  salable  as  fertilizer. 
Recently,  Mr.  Westinghouse  made  the  suggestion  that 
the  garbage  of  New  York  be  utilized  in  the  manu- 
facture of  gas  to  be  used  for  fuel  purposes.  He  esti- 
mates that  New  York  produces  about  509,000  kilograms 
of  garbage  annually.  Dr.  Hutchinson  estimates  that 
450  grams  of  this  refuse  have  a  maximum  theoretical 
heating  value  of  approximately  2000  calories,  and  that 
if  all  of  this  energy  could  be  recovered  in  the  form  of 
gas  it  would  require  3.85  kilograms  of  refuse  per  unit 
(kilowatt-hour)  of  electrical  energy,  and  that  ' '  a  consid- 
eration of  the  elementary  principles  involved  shows  a 
probable  relation  of  6.8  kilograms  of  refuse  per  unit 
(kilowatt-hour)  in  comparison  with  11. 3  kilograms, 
deduced  from  extensive  tests  with  steam."  These  sug- 
gestions are  of  the  greatest  financial  as  well  as  sanitary 
importance,  and  seem  to  offer  something  which  will 
not  only  favor  the  more  systematic  collection  of  gar- 
bage, but  also  its  disposal  to  the  financial  advantage  of 
the  community. 

Where  the  municipal  authorities  fail  to  provide  the 
necessary  system  for  the  removal  and  disposal  of  garbage 
the  novel  method  of  disposing,  introduced  several  years 
ago,  may  be  adopted  by  the  individual  householder. 
This  is  domestic  disposal  in  a  special  apparatus  attached 
to  the  kitchen  range.  It  consists  of  a  perforated  sheet- 
iron  basket,  with  a  tight  bottom  and  a  capacity  of  two  to 
three  liters.  It  is  inserted  into  an  expanded  section  of 
the  stove-pipe,  a  short  distance  above  the  kitchen  range, 
and  allows  the  hot  air  and  smoke  to  pass  on  all  sides  of 
the  basket.  It  is  easily  withdrawn  from  its  position  and 
replaced  with  one  hand.  The  garbage  is  placed  into  the 
basket  as  fast  as  it  accumulates,  and  the  contents  are  re- 
moved once  a  day.  It  dries  to  charcoal  without  burning, 
and  becomes  an  excellent  fuel  for  kindling  the  fire  in  the 
morning.  It  does  not  impair  the  use  of  the  stove,  nor 
interfere  with  the  draught,  causes  no  odors,  and  does  not 
require  any  extra  fuel. 


COLLECTION  AND  REMOVAL  OF  GARBAGE.    177 

For  hotels,  hospitals,  or  other  public  institutions  some- 
thing of  greater  capacity  must  be  provided  for  the  dis- 
posal of  the  garbage.  To  meet  this  demand  a  portable 
furnace  has  been  devised,  occupying  about  one-third  of  a 
square  meter  of  space,  with  an  independent  chimney 
connection,  which  will  destroy  the  waste  in  quantities  of 
nearly  a  barrel  at  once.  This  apparatus  has  a  garbage 
receptacle  or  retort  of  cast  iron,  cylindrical  in  form,  with 
a  cast-iron  grate  at  the  bottom.  This  retort  is  suspended 
30  to  40  centimeters  above  the  fire  pot  in  the  furnace, 
and  the  whole  is  encased  in  a  jacket  of  heavy  sheet  iron. 
In  operating,  the  retort  is  filled  with  garbage  introduced 
through  the  charging  door,  a  moderate  fire  is  started,  and 
the  process  of  cremation  begins.  A  simple  arrangement 
of  air  jets,  automatically  actuated  by  the  natural  draught 
of  the  chimney,  exhausts  all  the  smoke  and  odors  of  the 
burning  garbage  from  the  retort  and  carries  them  down 
and  through  the  furnace  fire,  so  that  nothing  but  the 
thoroughly  purified  and  odorless  gases,  liberated  by 
combustion,  can  escape  into  the  chimney  flue.  Such  an 
apparatus  requires  a  comparatively  small  amount  of  fuel. 
12 


CHAPTER  VII. 
FOOD   AND   DIETING. 

Not  only  the  health  and  strength  of  the  body,  but  the 
intellectual  and  moral  character  as  well,  are  dependent 
upon  the  nature  and  quantity  of  the  food-supply.  For 
this  reason  the  question  of  food  and  diet  is  most  complex, 
and  the  sanitary  phase  of  it  is  not  the  most  important 
one.  It  is,  however,  of  sufficient  importance  to  demand 
consideration  in  connection  with  general  hygienic  condi- 
tions, because  of  its  relation  to  the  welfare  of  man  in  gen- 
eral, and  because  of  the  dangers  that  arise  from  improper 
food  materials,  and  also  because  of  the  influence  upon 
health  of  excessive,  as  well  as  deficient,  amounts  of  food. 

The  late  Dr.  Atwater  defined  food  as  follows:  "Food 
is  that  which,  when  taken  into  the  body,  builds  up  its  tis- 
sues and  keeps  them  in  repair,  or  which  is  consumed  in 
the  body  to  yield  energy  in  the  form  of  heat  to  keep  it 
warm  and  create  strength  for  its  work. ' ' 

Chemical  Composition  of  the  Body. — In  order  to 
understand  the  needs  of  the  body  in  the  shape  of  food  to 
maintain  its  form  and  character,  it  will  be  necessary  to 
consider  briefly  its  chemical  constituents.  These  are 
both  organic  and  inorganic  in  their  nature,  composed  of 
the  following  elements  combined  into  a  number  of  com- 
pounds :  Hydrogen,  oxygen,  nitrogen,  carbon,  chlorin, 
fluorin,  sulphur,  silicon,  phosphorus,  potassium,  sodium, 
lithium,  calcium,  magnesium,  and  iron. 

The  inorganic  constituents  of  the  body  are  water, 
which  comprises  about  two-thirds  of  its  weight;  different 
gases,  such  as  oxygen,  hydrogen,  nitrogen,  carbon 
dioxid,  ammonia,  hydrogen  sulphid,  and  marsh  gas; 
salts,  such  as  sodium  chlorid,  calcium  phosphate  (which 
forms  more  than  one-half  the  substance  of  the  bones), 
calcium   carbonate  and   fluorid,  sodium    and   potassium 

178 


CHEMICAL  COMPOSITION  OF  THE  BODY.      179 

sulphate,  potassium  and  ammonium  chlorid,  sodium,  po- 
tassium, and  magnesum  phosphate,  and  sodium  carbon- 
ate and  bicarbonate ;  hydrochloric  acid;  silica;  andiron. 

The  organic  constituents  may  be  divided  into  the 
nitrogenous  and  non-nitrogenous  bodies,  of  which  the 
nitrogenous  are  the  most  numerous.  They  consist  of 
the  albuminous  bodies,  or  proteids;  the  albuminoid  sub- 
stances; certain  complex  bodies,  such  as  the  ferments, 
and  coloring-matters,  the  ammonia  derivatives.  The 
non-nitrogenous  bodies  consist  of  two  groups,  fats  and 
carbohydrates. 

All  of  these  various  elements  and  chemical  combina- 
tions, constituting  the  composition  of  the  body,  must  be 
supplied  in  the  food-supply  in  order  that  it  may  perform 
its  normal  functions  and  obtain  energy  for  all  of  man's 
activities  in  life.  Under  normal  physiologic  conditions 
the  amount  of  material  absorbed  from  the  food  is  about 
equal  to  that  which  is  thrown  oflf  by  the  excretory 
organs.  During  the  period  of  growth  the  amount 
absorbed  exceeds  the  amount  excreted,  while  in  most 
acute  diseases  the  amount  excreted  is  far  in  excess  of  the 
amount  absorbed,  and,  consequently,  the  body  wastes. 
The  body  increases  or  diminishes  in  weight  proportion- 
ately as  the  amount  of  material  absorbed  from  the  food 
is  greater  or  less  than  the  amount  excreted.  A  man  of 
average  weight  and  activity  takes  about  325  grams 
of  dry  solid  matter  and  from  1500  to  2000  grams  of 
water,  while  about  550  grams  of  oxygen  are  absorbed 
by  the  lungs  per  day.  Of  the  solids  taken,  about  40 
grams  are  eliminated  by  the  intestines,  and  the  remaining 
285  grams  by  the  other  excretory  organs.  The  oxygen 
taken  in  is  also  excreted  by  these  organs,  after  having 
been  utilized  ;  the  latent  or  potential  energy  of  the  food 
being  converted  into  kinetic  energy.  The  body  loses  in 
this  way  about  one-twentieth  of  its  weight  daily,  and 
this  loss  must  be  made  up  from  the  food  ingested. 

By  latent  or  potential  energy  is  meant  the  energy 
capable  of  performing  work  when  called  upon;  such,  for 
example,  as  resides  in  a  suspended  weight.      By  kinetic 


i8o  FOOD  AND  DIETING. 

energy  is  meant  energy  which  is  doing  work;  such  as 
the  force  exerted  by  the  weight  in  falling  to  the  ground. 
Heidenhain  calculated  that  four-fifths  of  the  total  energy 
of  the  body  takes  the  form  of  heat.  It  may  be  stated, 
therefore,  that  the  body  is  a  machine  for  converting 
potential  energy  into  kinetic  energy.  The  potential 
energy  is  supplied  by  the  food,  and  the  metabolism  of 
the  body  converts  this  into  the  kinetic  energy  of  heat 
and  mechanical  power. 

Potential  Bnergy  in  Food. — The  potential  energy 
contained  in  any  substance  is  determined  by  ascertaining 
the  amount  of  heat  that  is  produced  by  its  complete  com- 
bustion. The  potential  energy  contained  in  any  substance 
is  expressed  in  calories.  By  a  calorie  is  meant  the  amount 
of  heat  required  to  warm  i  gram  of  water  i  degree  centi- 
grade. This  is  the  "vSmall  calorie,"  as  distinguished  from 
the  "large  calorie,"  which  is  equivalent  to  the  amount  of 
heat  required  to  warm  i  kilogram  of  water  i  degree  centi- 
grade (kilogram-degrees) .  The  large  calorie  is,  therefore, 
looo  times  greater  than  the  small  calorie  and  is  used  when 
speaking  of  large  quantities,  and  the  smaller  figure  is 
used  when  it  would  be  more  convenient.  The  amount 
of  heat  given  off  by  the  human  adult  body  per  day  is 
equal  to  the  heat  required  to  warm  2,500,000  grams,  or 
2500  kilograms,  of  water  i  degree  centigrade,  and  this 
amount  of  heat  is  generated  by  the  body  each  day  from 
the  food  ingested.  According  to  Konig,  the  more  com- 
mon food-stuffs  have  values  as  fuel  as  follows : 

I  gram  of  dry  meat  yields 5I03    calories. 

I  gram  of  albumin  yields 499^  " 

I  gram  of  sugar  yields 3227  " 

I  gram  of  starch  (arrowroot)  yields 3912  "     " 

I  gram  of  butter  yields 7264  " 

I  gram  of  suet  yields 9096  " 

I  gram  of  vegetable  fibrin  yields 6231  " 

I  gram  of  casein  (milk)  yields 57^5  " 

I  gram  of  fibrin  (blood)  yields 5709  " 

I  gram  of  peptone  (Schuhardt)  yields 5334  " 

I  gram  of  glutein  yields 5943  " 

I  gram  of  chondrin  yields 49°9  " 

I  gram  of  urea  yields 2537  *' 


POTENTIAL   ENERGY  IN  FOOD.  i8i 

I  gram  of  Liebig's  meat-extract  yields 3206  calories. 

I  gram  of  fat  (extracted  with  cold  ether)  yields       9686  " 

I  gram  of  fresh  rye  bread  yields 2727  " 

I  gram  of  dry  rye  bread  yields 4421         " 

I  gram  of  fresh  wheat  bread  yields 2807         " 

I  gram  of  dry  wheat  bread  yields 4302         " 

When  we  compare  the  nutrients  in  respect  to  their 
fuel  values  with  their  capacities  for  yielding  heat  and 
mechanical  power,  a  gram  of  lean  meat  or  albumin  of 
egg  is  just  about  equivalent  to  i  gram  of  sugar  or  starch, 
and  a  little  over  2  grams  of  either  would  be  required  to 
equal  i  gram  of  fat  meat  or  butter.  These  are  called 
isodynamic  values.  Compared  with  each  other,  100 
grams  of  animal  albumin  are  isodynamic  with  52  grams 
of  fat,  114  grams  of  starch,  or  129  grams  of  dextrose; 
100  grams  of  fat  are  isodynamic  with  243  grams  of  dry 
flesh  or  225  grams  of  dry  syntonin. 

The  food  is  utilized  in  the  body  for  the  following  dif- 
ferent purposes:  To  form  the  tissues  and  fluids  of  the 
body;  to  repair  the  waste  in  the  tissues;  it  is  stored  up 
in  the  body  for  future  consumption;  it  is  consumed  as 
fuel,  its  potential  energy  being  transformed  into  heat, 
muscular  or  other  forms  of  energy;  or,  in  being  con- 
sumed, it  protects  the  tissues  or  other  food  from  con- 
sumption. 

The  proteid  nutrients  form  tissue,  and  also  serve  as 
fuel;  the  fats  form  fatty  tissue,  and  also  serve  as  fuel;  the 
carbohydrates  are  transformed  into  fat  and  serve  as  fuel. 

The  mechanical  energy  obtainable  from  various  arti- 
cles of  food  is  dependent  upon  the  amount  of  potential 
energy  stored  up  in  the  food,  which  is  expressed  in  terms 
of  calories,  and  the  extent  to  which  the  processes  of  the 
body  can  liberate  and  apply  this  energy.  For  instance, 
a  gram  of  albumin  gives  rise  to  a  certain  amount  of  heat 
when  burned  in  oxygen;  but  in  the  body  thorough  oxi- 
dation does  not  take  place,  because  some  of  the  con- 
stituents of  the  albumin  are  given  off"  incompletely  oxi- 
dized in  the  form  of  urea.  A  gram  of  sugar,  on  the 
other  hand,  is  generally  completely  oxidized,  being  con- 


1 82  FOOD  AND  DIETING. 

verted  into  carbon  dioxid  and  water,  and  its  actual 
energy  in  the  body  is  equal  to  its  theoretical  energy. 
The  mechanical  energy  obtainable  from  the  transforma- 
tion of  albumin  is  arrived  at  by  multiplying  the  number 
of  grams  of  its  several  constituents  by  a  number,  deter- 
mined by  exact  experiment,  representing  the  amount  of 
heat  produced  by  the  oxidation  of  i  gram  of  carbo- 
hydrate, fat,  or  proteid  to  water,  carbon  dioxid,  and  urea. 
According  to  Rubner,  the  average  calorific  value  of 
proteid  matter  is  4124  calories — that  is,  i  gram  of  proteid 
oxidized  to  urea  yields  4124  gram-degrees  (or  4.  i  kilo- 
gram-degrees) of  heat;  i  gram  of  fat  yields  9321  calories 
(9.3  kilogram-degrees)  ;  and  i  gram  of  carbohydrate 
(starch)  yields  41 16  calories  (4.1  kilogram-degrees).  Ap- 
plying these  numbers  to  Voit's  diet  for  a  man  of  70 
kilos  doing  hard  muscular  work,  we  obtain  in  round 
numbers: 

105  grams  of  assimilated  proteid  x  4.1  =    430  kilogram-degrees. 
56  grams  of  fat  x  9.3=     52p  " 

500  grams  of  carbohydrate  x  4.I  =  2050  " 

3000  kilogram- degrees, 

or  3,000,000  calories,  as  the  potential  energy  of  the  food. 
This  amount  may  be  taken  as  the  average  required  for  a 
man.  For  women  the  amount  is  somewhat  less  than 
this,  both  absolutely  and  relatively.  For  children, 
though  absolutely  less,   it  is  relatively  greater, 

Bnergy  Derivable  from  Food. — In  order  to  calcu- 
late how  much  mechanical  work  can  be  performed  by,  or 
is  equal  to,  the  potential  energy  expressed  in  calories,  we 
must  know  the  relation  between  heat  and  motion. 
According  to  Landois,  the  energy  required  to  heat  i 
gram  of  water  i  degree  centigrade  would  raise  a  weight 
of  425.5  grams  to  a  height  of  i  meter;  or  425.5  grams 
of  water  falling  through  i  meter  would  raise  the  tem- 
perature of  I  gram  of  water  i  degree  centigrade.  The 
mechanical  equivalent  of  the  calorie  is  obtained  by  mul- 
tiplying the  calories  by  425.5,  and  is  expressed  as  a 
gram-meter.     If  we  multiply  the  calorific  value  of  the 


ENERGY  DERIVABLE  FROM  FOOD.  183 

alimentary  principles  by  425.5,  we  obtain  the  mechanical 
energy  of  i  gram  of  each,  as  follows: 

Proteids 4124  x  425.5  =  1754  meter-kilos. 

Fats 9321  X  425.5  =  3966 

Carbohydrates 4116  x  425.5  =  1751  " 

In  order  to  ascertain  the  mechanical  energy  contained 
in  any  diet  we  multiply  the  number  of  grams  of  each 
alimentary  principle  by  the  figures  representing  the 
mechanical  energy  of  each.  Taking  the  standard  diet 
of  Moleschott  for  a  man  performing  moderate  work  we 
obtain  the  following  results: 

Proteids 14S  x  1754  =      254,330 

Fats 45  x  3966  =      193,470 

Carbohydrates 605  x  1751  =  1,059,355 

I>507,i55  meter-kilos. 

According  to  Hueppe,  the  loss  of  heat  from  the  body 
during  work  is  as  follows: 

Loss  through  radiation  and  conduction  ....  1789  large  calories. 

Loss  through  evaporation  from  the  skin     .    .    .  384  large  calories. 

Loss  through  evaporation  from  the  lungs   .    .    .  192  large  calories. 

Total     2365  large  calories. 

Loss  of  heat  during  rest 1500  large  calories. 

Excess  during  work 865  large  calories. 

He  gives  the  following  dietaries  from  which  he  estimates 
the  amount  of  energy  available  for  mechanical  work: 


1 84 


FOOD  AND  DIETING. 


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ENERGY  DERIVABLE  FROM  FOOD. 


185 


The  available  energy  for  mechanical  work  in  the  above 
diets  (the  mechanical  equivalent  —  425),  after  deducting 
the  excess  of  heat  lost  during  work,  is  as  follows  : 

B,  .  .  1266-865  =  401  calories  X  425  =  170,425  kgm.  =  14.5  per  cent, 

Bj  .  .  1273- 865  =408  calories  X  425  =  173,400  kgm.=  15.0       " 

C   .  .  1419-865  =  554  calories  X  425  =  235,450  kgm.=  19.0       " 

D   .  .  1449  -  865  =  584  calories  X  425  =  248,200  kgm.  =  20.0       " 

The  maximum  day's  work  of  eight  hours,  tested  on  the 
ergograph,  ranges  from  200,000  to  250,000  meter-kilos. 

The  mechanical  energy  present  in  an  ordinary  diet 
may,  therefore,  be  estimated  at  1,250,000  meter-kilos. 
The  work  and  heat  of  the  body  use  up  the  following 
amounts,  according  to  De  Chaumont  : 

Work  of  circulation 75,000  meter-kilos. 

Work  of  respiration 12,000  " 

Calorific  work 781,000  " 

External  work  (93,000  kgm.) 465,000  " 

1,333,000  meter-kilos. 

This  total  is  in  excess  of  the  total  energy  contained  in 
the  standard  diet,  but  this  is  unavoidable,  according  to 
Davies,  "in  calculations  of  such  an  approximate  nature 
as  the  present  one  ;  the  important  point  as  regards  diet- 
ing is  the  proportion  that  should  exist  between  the  differ- 
ent objects  for  which  the  total  energy  is  supplied." 

The  following  may  be  taken  as  an  approximate  basis 
for  the  calculation  of  diets  accordinof  to  size  and  work  : 


Proximate. 

For  subsistence. 

For  work  of  93,000 

meter-kilos  per 

diem. 

For  work  of  100,000 

meter-kilos  per 

diem. 

Aliment. 

Grams  per  kilogram 
of  body-weight. 

Grams  per  kilogram 
of  body-weight. 

Grams  per  kilogram 
of  body-weight. 

Proteids 

Fats 

Carbohydrates    .... 
Salts 

1.044 
0.412 
5.000 
0.163 

1.903 
1. 132 

5-937 
0.380 

2.06 
1.32 
6.38 
0.47 

Total 

6.619 

9-352 

10.23 

i86 


FOOD  AND  DIETING. 


Dietary  Standards  (Atwater). 


European  standards  for  daily  dietaries. 

Nutrients. 

Fuel 
value. 

Nutri- 
tive  ra- 
tio. 

Protein. 

Fats. 

Carbohy- 
drates. 

I 

2 

3 
4 
5 
6 

7 
8 
9 

lO 

II 

12 

13 
14 
IS 

Children,  one  to  two  years,  average 

Children,  two  to  six       "             " 

Children,  six  to  fifteen  "             " 

Aged  woman 

Aged  man 

Woman  at  moderate  work 

Man         (Voit) 

Man         "       hard        "  (Voit) 
Man         "  moderate  "  (Moleschott) 
Man         "         "               (Wolffj 
Subsistence  diet  (Playfair) 
Diet  in  quietude  (Playfair) 
Adults  in  full  health  ( Playfair) 
Active  laborers  (Playfair) 
Hard-worked  laborers  (Playfair) 

Grams. 
30.0 
60.0 
85.0 
90.0 

IIO.O 

loo.o 
130.0 
160.0 

145.0 

140.0 

65.0 

80.0 

130.0 

170.0 

205.0 

Grams. 
40.0 

45 -o 

50.0 

55 -o 
75-0 
50.0 
60.0 

IIO.O 

45 -o 
40.0 
I5-0 
30.0 
5S-0 
80.0 
80.0 

Grams. 
85.0 
220.0 
360.0 
285.0 

385-0 
440.0 
550.0 

495 -o 
605.0 
595 -o 
375 -o 
375-0 
185.0 
625.0 
625.0 

Calories. 

765 
1420 
2040 
i860 
2475 
2425 
3055 
3370 
3160 
3030 
1760 
1950 
3140 
3630 
3750 

S-7 

5-3 
5.6 
4-7 
5-0 
5-4 
5-3 
4-7 
4-9 
4-9 
6.5 
5-7 
5.4 
4.7 
3-9 

American  Standards. 

I 
2 
3 
4 
S 
6 

Woman  with  light  muscular  exercise 
Woman  with  moderate   "       exercise 
Man  without  muscular  work              ) 
Man  with  light     "             "                  J 
Man  with  moderate  muscular  work 
Man  with  hard 

90 

100 

112 

125 

2400 
2700 

3000 

3500 
4500 

1:5-5 
1:5.6 

1:5-5 

1:5-3 
1:6.3 

The  figures  of  the  foregoing  tables  represent  the 
amounts  of  nutrients  which  different  investigators  have 
estimated  to  be  proper  for  the  daily  food  of  different 
classes.  The  minimum  standard  of  daily  diet,  approxi- 
mately calculated,  may  be  given  as  follows:^ 

Minimum  Standard  of  Daily  Diet. 


Child  up  to  one  and  one-half  years  of  age  . 

Child  from  six  to  fifteen  years 

Man,  at  moderate  labor .    . 

Woman,  at  moderate  labor       

Man,  at  severe  labor 

Man  of  advanced  age      

Woman  of  advanced  age 


Albumin. 

Fat. 

Carbohy- 
drates. 

Grams. 

Grams. 

Grams. 

20-36 

30-45 

60-90 

70-80 

37-50 

250-400 

118 

56 

500 

92 

44 

400 

120-145 

100 

500 

100 

68 

350 

80 

20 

260 

GesundheUsbilchlein,  Berlin,  1896,  Imperial  Board  of  Health, 


ENERGY  DERIVABLE  FROM  FOOD. 


187 


Shortly  after  the  commencement  of  the  European 
War  the  German  Government  called  into  service  a 
committee  of  scientific  experts,  known  as  the  Eltzbacher 
Commission,  to  study  the  food  problem  and  devise 
defensive  measures  for  the  empire.  This  commission 
based  its  calculations  of  the  needs  of  the  people 
with  regard  to  the  protein  of  the  food  on  data  pre- 
sented in  the  following  table).  The  amounts  adopted 
by  the  commission  are  higher  than  the  figures  promul- 
gated by  Chittenden  as  representing  the  physiologic 
needs  of  the  human  body,  but  lower  than  A.  B.  Taylor's 
calculations  of  the  physiologic  needs  of  man  as  based  on 
war-time  conditions: 


Protein  needs. 

Protein  needs. 

Per  capita. 

Man  ration. 

Per  capita. 

Man  ration. 

Eltzbacher  Commission.^ 

2.30  gm. 
2.15  gm. 
1.50  gm. 

2.83  gm. 
2.50  gm. 
1.80  gm. 

2380 
2510 
2030 

3000 
3300 
2600 

A  E.  Taylor.  .              

Chittenden 

Graham  Lusk  points^  out  that  the  Eltzbacher  Com- 
mission failed  to  take  into  account  the  increased  food 
requirements  of  growing  children. 

According  to  Hueppe,  the  following  reductions  must 
be  made  because  all  of  the  nutritive  materials  in  the  food 
ingested  are  not  absorbed :  In  general,  i  .5  per  cent,  of  the 
albumin  is  not  absorbed.  Of  the  fat  of  pork,  only  98  per 
cent,  is  absorbed;  of  beef,  90  percent.  Mixed  with  meat 
the  digestibility  of  animal  fats  averages  83  per  cent. 
Beef,  with  a  content  of  20.91  per  cent,  of  nitrogenous 
matter  and  5.19  per  cent,  of  ether  extract,  has  a  gross 

^Saturday  Evening  Post,  Feb.  17th,  24,  and  March  3,  1917. 
"^Science,  April  13,  191 7. 


1 88  FOOD  AND  DIETING. 

value  as  follows :  loogm.  =20.91  X  4124+  5.19  X  9321  = 
86.232  +  48.376  =  134  calories.  If  we  assume  that  the 
digestibility  of  the  albumin  is  97.5  per  cent,  and  that  of 
the  fat  83  per  cent.,  then  the  true  value  is  as  follows: 
100  gm.  =  86.232  X  0.975  +  48.376  X  0.83  =  84.076  + 
40.152  =  124  calories. 

This  calculation  holds  true  for  meat  free  from  bones, 
but  in  the  calculation  of  a  general  dietary  a  reduction  of 
15  per  cent,  must  be  made  for  bones.  One  hundred 
grams  of  commercial  meat  with  15  per  cent,  of  bones 
contain  17.78  percent,  of  nitrogenous  matter  and  4.41 
per  cent,  of  ether  extract;  and  calculated  as  above, 
possess  a  true  value  of  105  calories. 

According  to  von  Reckenberg,  the  digestibility  of 
meat  per  100  grams  of  substance  is  as  follows  : 


Physiologic 

Nitrogenous 

Ether 

energy. 

substance. 

extract. 

without  1      with 

(Albumin.) 

(F 

at,) 

reference  to  di- 

gestibility. 

Con- 

Digesti- 

Con- 

Digesti- 

Gross 

True 

tent. 

ble. 

tent. 

ble. 

value. 

value. 

gm. 

gm. 

gm. 

gm. 

Calories. 

Calories. 

f  Medium  fat,  without 

Beef. 

!       bones     

20.91 

20.39 

5-19 

4.31 

132  1 

122 

Medium  fat,  with  15 

per  cent,  of  bones 

17.78 

17.33 

4.41 

3.66 

112 

104 

(  Fat,  without  bones  . 

14-54 

14.18 

37-34 

30.99 

409 

348 

Pork  . 

\  Fat,    with     10    per 

(      cent,  of  bones  .    . 

13.09 

12.76 

33-61 

27.89 

368 

313 

A    herring,  135    gm.,   37  per 

cent 

waste 

16.07 

15.67 

14.36 

11.92 

199 

174 

Fat,  smoked 

2.6 

2.54 

77.80 

64.57 

742 

617 

Lard, 

rendered 

0.26 

0.25 

99.04 

94.04 

934 

887 

The  digestibility  of  the  nitrogenous  substance  can  be 
assumed  to  be  the  same  for  all  kinds  of  meat.  One  gram 
of  ether  extract  represents  9415  calories  in  pork,  the  bone 
refuse  being  reckoned  as  10  per  cent.  Rendered  swine 
and  beef  fat,  as  well  as  the  fat  of  fish  and  geese,  may  be 

1  In  these  calculations  albumin  is  reprented  as  4003,  and  fat  at  9320 
calories. 


NUTRITIVE  VALUE  AND  COST  OF  FOOD.     189 


calculated  as  in  the  case  of  pork  fat,  while  the  fat  of 
other  animals  must  be  calculated  as  in  the  case  of  beef. 
In  smoked  fat  i  gram  of  ether  extract  represents  9400 
calories,  because  the  ether  extract  does  not  contain  pure 
fat. 

Nutritive  Value  and  Cost  of  Food. — The  following: 
tables  are  based  on  the  tables  in  the  Appendix  of  "  Foods: 
Nutritive  Value  and  Cost,"  by  Prof  Atwater,  Farmer^ s 
Bulletin  No.  23,  issued  by  the  U.  S.  Department  of 
Agriculture.  In  each  of  the  tables  the  fuel  value  has 
been  expressed  in  calories  of  the  metric  system  instead 
of  the  amounts  contained  in  the  tables.  The  weight  of 
the  food  materials  has  been  expressed  in  grams  instead 
of  in  ounces  and  pounds.  ' '  Table  B  gives  the  propor- 
tions of  ingredients  in  a  number  of  materials  as  found 
by  analysis  of  specimens  collected  for  the  most  part  in 
New  York  and  New  England  markets." 

Table  A. — Amounts  of  Nutrients  furnished  for  S5  cents 
in  Food  Materials  at  Ordinary  Prices. 


Food  materials  as  purchased. 


Beef,  sirloin 

Beef,  round 

Beef,  neck 

Mutton,  leg 

Ham,  smoked 

Salt  pork 

Codfish,  fresh 

Codfish,  dried  salt 

Mackerel,  salt 

Oysters,  25  cents  per  quart  . 
Eggs,  25  cents  per  dozen  .  . 
Milk,  8  cents  per  quart  .  .  . 
Cheese,  whole  milk  .... 
Cheese,  skimmed  milk  .  .  . 
Butter,  25  cents  per  pound  . 
Sugar,  5  cents  per  pound  .    . 

Wheat   flour 

Wheat  bread 

Oatmeal 

Beans  

Potatoes,  60  cents  per  bushel 


12-5 

14.7 


25 

5 

2-5 

5 


Twenty-five  cents  will  pay  for — 


Grams. 

500 

780 
1565 

625 

780 
1250 
1250 
156s 
1250 
1000 

850 
3' 25 

835 
1250 

500 
2500 
5000 
2500 
2500 
2500 
12,500 


Nutrients. 


Total.     Protein 


Grams. 

155-0 

235-0 

465.0 

190.0 

385.0 

1045.0 

135-0 

255-0 

370.0 

120.0 

190.0 

385-0 

545 -o 

675.0 

430.0 

2445.0 

4350.0 

1670.0 

2260.0 

2110.0 

2135.0 


Grams. 

75-0 
140.0 
245.0 

95.0 
115.0 

10 


Fats. 


Grams. 
80.0 
95.0 
220.0 
95-0 
270.0 
1035.0 


5-0 

185.0 
15.0 
85.0 

125.0 

295.0 
85.0 

425.0 

55-0 
40.0 


Carbo- 
hydrat's 


145.0 
15.0 
iio.o 

2445.0 
3745-0 
1410.0 
1710.0 
1480.0 
1900.0 


Fuel 
value. 


Calories. 

970 
133s 
2755 
1170 
2705 
8775 

510 

985 
2275 

520 
"15 
2030 
3455 
2910 
3615 
9100 
16,450 
6400 
9225 
8075 
8000 


190 


FOOD  AND  DIETING. 


Table  B.  —  Composition  of  Different  Food  Materials. 


Food  Materials. 


Aniiiial  foods  as  purchased. 

Beef: 

Neck 

Shoulder 

Chuck  rib 

Rib 

Sirloin 

Round  steak      

Side,  without  kidney  fat    .    . 

Rump,  corned 

Flank,  corned 

Veal,  shoulder 

Mutton  ; 

Shoulder 

Leg 

Loin      ...        

Side,  without  kidney  fat  .  . 
Pork: 

Shoulder  roast,  fresh  .... 

Ham,  salted,  smoked      .    .    . 

Chicken 

Turkey 

Eggs,  in  shell 

Fish,  etc.  : 

Flounder,  whole 

Bluefish,  dressed 

Codfish,  dressed 

Shad,  whole 

Mackerel,  whole 

Halibut,  dressed 

Salmon,  whole      

Salted  codfish 

Smoked  herring 

Salted  mackerel 

Canned  salmon 

Lobsters      

Oysters 

Animal  foods,  edible  portion. 
Beef: 

Neck 

Shoulder 

Chuck  rib 

Rib 

Sirloin 

Round     

Side,  without  kidney  fat    .    . 

Rump,  corned 

Flank,  corned 

Veal,  shoulder 

Mutton  • 

Shoulder 

Leg 

Loin 

Side,  without  kidney  fat    .    .    , 
Pork  : 

Shoulder  roast,  fresh 

Ham,  salted,  smoked     .    .    .    . 

Fat,  salted 

Sausage : 

Pork 

Bologna 

Chicken 


c 


12.6 
14.6 
21 
19.5 

7-8 
19.2 

5 
12. 1 

179 

16.3 
18. 1 
15.8 
17-3 

14.6 
11.4 
38.2 
324 
13-7 

66.8 
48.6 
29.9 
50.1 
44.8 
17.7 

35-3 
42.1 
50.9 
40.4 

4-9 
62.1 

82.3 


Edible  portion 


49.6 
55-8 
49-5 
38.2 
48.3 
60.9 
44-3 
70.8 

43  7 
56.7 

49 
50.6 
41.5 
44.2 

43 

36.8 

44.6 

44-7 

63.1 

27.2 

43 

58.5 

35-2 

40.4 

61.9 

40.6 

40.5 

19.2 

28.1 

59. 3 

31 

15-4 


62 
63.9 

58 


Nutrients. 


30.4 
31.6 

35-9 
40.8 
32.2 
31-3 
36.5 
24.2 
44.2 
25.4 

34  7 
31-3 


42 

38 

42 
51 
17 
22 

23 

6 

II. I 
11.6 
14-7 
IS 
20.4 
24.1 
17.6 
29.9 
31-5 
35.8 

6.9 

2-3 


38 

36.1 

42 

51-9 

40 

31.8 

45.2 

41.9 

50.2 

3' -2 

41.4 
38.2 
50-7 
46-5 

49-7 

58.5 
87.9 

58.8 
37-6 
27.8 


15.6 

17 

15 

12.2 

15 

18 

13-9 
16.7 
12.4 
16.6 

15.1 
15 

12.6 
•4 

13.6 
14.8 
15-1 
16. 1 

12. 1 

5-2 
9.8 

10.6 
9.2 

ID 

iS.i 
14-3 
16 
20.2 
14.7 
19-3 
5-5 
I.I 


18.3 
15 
16  9 

16 

16.7 
•9 

13.8 


'4 
13-7 
20.1 
27.9 
16.4 
12.3 
21.8 
5-1 
29.2 

7-9 

18.8 
15-6 
29.5 
23.7 

28 
34-6 

1.2 

5-9 
10.2 

•3 
.6 
.2 

4.8 
4-3 
4-4 


15. 1 

15-3 

•7 


17-5 
15.6 
23-5 
35.6 
20.5 
10. 1 


33 
9.8 

22.4 
19 
35 
28.7 

32.8 

39-1 
82.8 

42.8 
IS.8 


1.2 

•9 


rt  g 


Cal. 
880 
895 

1125 

1405 
970 
855 

1180 
525 

1460 
640 

107s 
935 
1480 
1260 

1435 
1735 
330 
550 
6S5 

no 
210 
205 

375 
365 
465 
635 
315 
745 
910 
1005 

135 
40 


1100 
1020 
1320 
1790 
1210 

805 
1465 
1370 
1655 

790 

1280 
1 140 
1755 
1525 

1680 
i960 
3510 

2065 
1015 
540 


DIGESTIBILITY  OF  FOODS. 


191 


Table  B  {continued). 


Food  Materials. 


Turkey , 

Eggs 

Milk 

Butter 

Oleomargarin    ... 

Cheese: 

Full  cream      ,    . 
Skimmed  milk  .    , 

Fish: 

Flounder     ... 
Haddock     .    .    .    , 
Codfish    .... 

Shad 

Mackerel     .    .    .    , 

Halibut 

Salmon 

Salted  cod  .    .    .    , 
Herring,  salted 
Mackerel,  salted  , 
Oysters 


Vegetable  foods. 

Wheat  flour 

Graham  flour  (wheat)     .    . 

Rye  flour 

Buckwheat  flour 

Oatmeal  .     • 

Cornmeal 

Rice 

Peas 

Beans   

Potatoes ■ 

Sweet  potatoes      

Turnips 

Carrots 

Onions 

String  beans 

Green  peas 

Green  corn 

Tomatoes 

Cabbage      

Apples     .    ■ 

Sugar,  granulated    .... 

Molasses 

White  bread  (wheat)  .    .    . 
Boston  crackers 


(^   (A 


Edible  portion. 


66.2 
73-8 
87 


30.2 
41-3 


B1.7 
82.6 
70-6 
73-4 
75-4 
63.6 
53.6 
34-6 
43-4 
87.1 


12.5 

131 

13. 1 
14.6 

7.6 
15 
12.4 
12.3 
12.6 
78.9 
71. 1 
89.4 
88.6 
87.6 
87.2 
78.1 
81.3 
96 
91.9 
83.2 

2 
24.6 
32-3 

8.3 


Nutrients. 


33.8 
26.2 


69.8 
58.7 

15.8 
18.3 
17-4 
29.4 
26.6 
24.6 
36-4 


87.5 
86.9 
86.9 

85.4 
92.4 

85 

87.6 

87.7 

87.4 

21. 1 

28.9 

10.6 

II. 4 

12.4 

12.8 

21.9 

18.7 

4 

8.1 
16.8 


75-4 
67.7 
91.7 


23.9 
14.9 
3.6 


28.3 
38.4 

13.8 
16.8 
15.S 
18.6 
1S.2 
18.3 

21.6 

21.4 
36.4 
17-3 
6 


11.7 

6.7 

6.9 

15. 1 

19.2 

7-4 

26.7 

23.1 

2.1 

1-5 

1.2 

I.I 

1-4 

2.2 

4-4 


8-7 
10.5 

4 


35-5 
6.8 


•7 

■3 

■4 

9-5 

7-1 

5-2 

13.4 

-3 

15-8 

26.4 

1.2 


1-7 

9-9 


4-7 

•5 


1.8 

8.9 


4-2 
4.6 


■5 
1.8 

-7 


1-4 

•4 

2.9 

3-1 


810 

721 

323 

3615 

3605 

2070 
1165 

285 
32s 
310 
745 
640 
560 
965 
410 
^345 
i860 
1230 


1645 

1625 
1625 
1605 
1850 
1645 
1630 
3565 
1615 
375 
530 
185 
200 
225 

235 
405 

34S 
80 
155 
315 
1820 
1^60 
1280 
1895 


Digestibility  of  Foods. — In  general,  the  animal  foods 
are  somewhat  more  digestible  than  the  vegetable  foods. 
The  proteid  matter  of  ordinary  meats,  for  instance,  is 
practically  all  digested  when  eaten  in  moderate  quanti- 
ties by  healthy  persons  (97.5  per  cent.);  but  the  same 
person  might  digest  only  nine-tenths  of  the  proteid  mat- 
ter of  wheat,  and  not  more  than  three-fourths  of  that  of 
potatoes.     The  fat  of  meats  is  less  completely  digested. 


192  FOOD  AND  DIETING. 

The  sugar  and  starch  of  vegetables,  when  they  are  prop- 
erly cooked,  are  very  easily  and  completely  digested. 

According  to  the  experiments  of  Dr.  Beaumont  on 
Alexis  St.  Martin,  the  digestibility  of  different  food  sub- 
stances ranges  itself  in  the  following  order:  "Rice,  tripe, 
whipped  eggs,  sago,  tapioca,  barley,  boiled  milk,  raw 
eggs,  lamb,  parsnips,  roasted  and  baked  potatoes,  and 
fricasseed  chicken  are  most  easily  digested  in  the  order 
given — the  rice  disappearing  from  the  stomach  in  one 
hour,  and  the  fricasseed  chicken  in  two  and  three-fourths 
hours.  Beef,  mutton,  pork,  oysters,  butter,  bread,  veal, 
boiled  and  roasted  fowls  are  rather  less  digestible,  roast 
beef  disappearing  from  the  stomach  in  three  hours,  and 
roast  fowl  in  four  hours.  Salted  beef  and  pork  disappear 
in  four  and  a  quarter  hours." 

The  following  list  (Chambers)  shows  the  relative  digesti- 
bility of  different  articles  of  food:  "  Roast  mutton,  sweet- 
bread, boiled  chicken,  venison,  soft-boiled  eggs,  new 
toasted  cheese,  roast  fowl,  turkey,  partridge  and  pheasant, 
lamb,  wild  duck,  oysters,  periwinkles,  omelette,  tripe, 
boiled  sole,  haddock,  skate,  trout,  perch,  roast  beef, 
boiled  beef,  rump  steak,  roast  veal,  boiled  veal,  rabbit, 
salmon,  mackerel,  herring,  pilchard,  sprat,  hard-boiled 
and  fried  eggs,  pigeon,  hare,  duck,  goose,  fried  fish, 
roast  and  boiled  pork,  heart,  liver,  kidneys,  lobster, 
salted  fish,  crab." 

The  digestibility  of  food  depends  upon  the  nature  of 
the  food  substance,  its  hardness  and  cohesion,  and  on  its 
chemical  nature,  as  well  as  on  the  degree  to  which  it  is 
altered  by  cooking.  It  is  also  dependent  upon  the  indi- 
vidual characteristic  of  each  person,  the  digestive  power 
of  the  organs  of  digestion.  The  admixture  of  different 
classes  of  foods  also  aids  digestion;  some  of  the  accessory 
foods  probably  causing  an  increased  flow  of  the  digestive 
fluids.  The  degree  of  fineness  of  the  food  and,  conse- 
quently, the  thoroughness  of  mastication  are  important 
factors  in  favoring  digestion.  The  amount  of  food  taken 
at  a  time  also  plays  an  important  influence  in  digestion. 


COMPOSITION  OF  FOODS.  193 

Composition  of  Foods. — The  ordinary  food  materials 
consist  of  refuse  matter,  such  as  the  bones  of  meat  and 
fish,  the  shells  of  shellfish,  the  skin  of  potatoes,  and  the 
bran  of  wheat;  and  of  proteid  matter,  fats,  carbohydrates, 
and  salts. 

Prof.  Atwater,  in  his  reports  on  the  chemical  composi- 
tion of  food  materials,  uses  the  term  "protein,"  which 
"includes  nominally  the  total  nitrogenous  substance  of 
animal  and  vegetable  food  materials,  exclusive  of  the  so- 
called  nitrogenous  fats."  The  term  "proteid,"  as  used 
in  the  same"  reports,  "includes  (i)  the  simple  proteids,  e. 
g.^  albuminoids,  globulins  and  their  derivatives,  such  as 
acid  and  alkali  albumins,  coagulated  proteids,  proteoses, 
and  peptones;  (2)  the  so-called  combined  or  compound 
proteids;  (3)  the  so-called  gelatinoids  (sometimes  called 
'  glutinoids '),  which  are  characteristic  of  animal  con- 
nective tissue."  The  term  "albuminoids"  is  used  as  a 
"collective  designation  of  the  substances  of  the  first  two 
groups,  though  many  apply  it  to  all  three  of  these  groups. 
Of  late  a  number  of  investigators  and  writers  have 
employed  the  term  as  a  special  designation  for  com- 
pounds of  the  third  class."  The  term  "  non-proteid  " 
is  "  used  synonymously  with  the  term  non-albuminoid," 
and  includes  nitrogenous  animal  and  vegetable  com- 
pounds of  simpler  constitution  than  the  proteids.  The 
most  important  animal  compounds  of  this  class  are  the 
so-called  "nitrogenous  extractives"  of  muscular  and 
connective  tissue,  such  as  creatin,  creatinin,  xanthin, 
hypoxanthin,  and  allied  cleavage  products  of  the  pro- 
teids. The  non-proteid  nitrogenous  compounds  in  vege- 
table foods  consist  of  amids  and  amido-acids,  of  which 
asparagin  and  aspartic  acid  are  familiar  examples. 

The  total  nitrogenous  substance  is  estimated  by  deter- 
mining the  amount  of  nitrogen  present  and  multiplying 
the  product  by  the  factor  6. 25. 

The  fats  include  the  true  vegetable  and  animal  fats, 
such  as  the  fat  of  fat  meat,  the  fat  of  milk,  olive  oil, 
cottonseed  oil,  etc.,   and  various  other  substances,  such 

13 


194  FOOD  AND  DIETING. 

as  the  fatty  acids,  lecithins  (nitrogenous  fats),  and  the 
chlorophyls.  The  fats  contain  about  75  per  cent,  of 
carbon.  Under  carbohydrates  are  included  the  different 
sugars,  starches,  gums,  and  cellulose,  or  woody  fiber. 
These  substances  are  found  most  plentifully  in  the 
cereals,  as  wheat,  oats,  corn,  rye,  and  barley,  in  the 
Leguminosse,  and  in  the  different  roots,  tubers,  and  green 
vegetables. 

Under  mineral  foods  are  included  water,  phosphates, 
sulphates,  chlorids,  and  other  salts  of  potassium,  sodium, 
magnesium,  and  other  metallic  elements.  Of  these, 
sodium  chlorid  is  the  most  important,  its  presence 
exciting  assimilative  changes  and  assisting  in  the  secre- 
tion of  many  of  the  digestive  fluids,  especially  of  the 
gastric  juice;  and  so  necessary  is  it  to  the  organism  that 
when  it  is  supplied  in  insuflScient  quantity  it  is  retained 
by  the  tissues  and  not  excreted.  When  deprived  of  it 
animals  lose  in  weight  and  activity.  The  potassium 
salts  are  also  indispensable,  acting  as  exciters  of  the 
nervous  system  and  increasing  the  cardiac  pulsations. 
The  phosphates  are  of  importance  because  of  the  large 
amounts  required  to  maintain  the  normal  condition  of 
the  bones. 

Functions  of  the  Alimentary  Principles  of  Food* 
— The  various  nitrogenous  substances  in  foods  serve  the 
following  purposes  when  taken  into  the  system:  Forma- 
tion and  repair  of  the  tissues  and  fluids  of  the  body;  the 
regulation  of  the  absorption  and  utilization  of  oxygen; 
and  they  serve  as  regulators  of  digestion  and  assimilation, 
especially  with  reference  to  the  gelatin  group. 

Of  the  non-nitrogenous  substances  in  foods,  the  fats 
serve  to  supply  fatty  tissues  and  as  nutrition  to  the 
nervous  system.  They  also  supply  energy  and  animal 
heat  by  oxidation.  The  carbohydrates  also  serve  to 
supply  energy  and  animal  heat  by  oxidation,  and  they 
are  converted  into  fat  by  deoxidation,  and  stored  in  the 
body  for  future  use.  The  vegetable  acids  serve  to  main- 
tain the  alkalinity  of  the  blood  by  conversion  into  car- 


WA  TER  AS  FOOD.  I95 

bonates,  and  to  furnish  a  small  amount  of  energy  or 
animal  heat  by  oxidation. 

The  mineral  matters  of  food  serve  to  support  the  bony 
skeleton,  supply  hydrochloric  acid  for  digestion,  also  as 
regulators  of  energy  and  nutrition. 

In  addition  to  the  four  alimentary  principles  in  food, 
several  groups  of  substances,  which  are  not  included  in 
this  classification,  must  also  be  mentioned.  These  are 
the  condiments  and  beverages.  The  condiments  are  of 
importance  because  they  serve  to  give  flavor  to  food,  and 
stimulate  secretion  and  digestion,  though  they  have  but 
little  direct  influence  in  forming  tissue  or  in  supplying 
energy  and  heat. 

Besides  the  alimentary  principles  contained  in  food 
there  are  one  or  more  constituents,  the  exact  natm"e  of 
which  is  not  known,  called  the  vitamins,  but  the  absence 
of  which  leads  to  defective  nutrition.  Beriberi,  scurvy, 
and  probably  pellagra  are  conditions  of  malnutrition 
which  are  traceable  to  the  absence  of  certain  principles 
in  the  daily  dietary.  It  is  apparent  that  each  of  these 
conditions  is  due  to  the  absence  of  a  different  substance. 
It  is  of  the  greatest  importance  to  avoid  too  constant 
sameness  in  the  diet.  A  mixed  diet  which  is  varied  from 
day  to  day  and  from  season  to  season  is  the  best  safe- 
guard against  malnutrition. 

Water  as  Food.— Since  water  forms  about  two-thirds 
of  the  weight  of  the  body,  a  great  deal  of  fluid  must  be 
taken  into  the  system  in  order  to  balance  the  constant 
loss  through  the  excretions.  This  fluid  is  in  part  sup- 
plied by  the  food  as  usually  prepared,  but  a  large  pro- 
portion must  be  supplied  directly  as  water  or  in  the  form 
of  some  beverage,  as  tea,  coffee,  milk,  or  some  of  the 
alcoholic  or  non-alcoholic  beverages.  The  quantity  of 
water  required  daily  by  an  adult  person  is  usually  stated 
as  3  liters,  of  which  i  liter  is  contained  in  the  food  in- 
gested, and  the  other  2  liters  must  be  supplied  in  the 
form  of  plain  water  or  one  or  other  of  the  beverages 
named. 


196  FOOD  AND  DIETING. 

A  deficient  supply  of  water,  or  fluid  of  any  kind,  tends 
to  induce  aflfections  of  the  kidneys  and  bladder  from  the 
concentrated  condition  of  the  blood  and  excreta.  It  also 
manifests  itself  in  diminished  nervous  activity. 

The  supply  of  fluid  taken  should  be  so  regulated  as  not 
to  interfere  with  digestion.  Large  quantities  of  fluid 
taken  with,  or  shortly  after  the  meals,  will  dilute  the 
gastric  juice  to  such  an  extent  as  to  retard  digestion,  and 
thus  lead  to  disturbances  of  the  digestive  function.  The 
experiments  of  Hawk  and  his  associates  have  shown  that, 
contrary  to  the  generally  accepted  opinion,  copious  water- 
drinking  is  not  injurious.  In  fact,  in  many  instances  it 
was  found  beneficial  because  of  the  increased  elimination 
induced. 

DIFFERENT  VARIETIES  OF  FOOD. 

Animal  Foods;  Meat. —  The  flesh  of  herbivorous 
animals  is  most  commonly  used  for  food,  though  that  of 
the  pig,  an  omnivorous  animal,  is  also  used  extensively 
in  some  countries.  The  flesh  of  young  animals  is  more 
tender,  because  there  is  less  connective  tissue  between 
the  different  muscular  bands.  Atwater  has  found  that 
meat  and  fish  are  digested  to  the  same  extent  by  healthy 
men.  The  meat  derived  from  young  animals  is  less 
easily  digested  than  that  of  older  animals.  Cooked  meat 
is  more  difficult  of  digestion  than  raw  meat.  The  meat 
of  females  is  also  more  tender  and  less  coarse  than  that 
of  males.  The  flesh  of  wild  animals  is  less  fatty,  higher 
in  color,  and  richer  in  flavor  and  extractives  than  that  of 
domestic  animals. 

The  nitrogenous  substances  of  meat  are  albumin, 
creatin,  creatinin,  sarkin,  xanthin,  inosin,  uric  acid,  and 
urea.  The  muscular  sheaths  and  connective  tissue  con- 
tain also  myosin.  The  proportion  of  albumin  ranges 
from  0.6  to  4.56  per  cent.;  Liebig  gave  the  average 
amount  as  2.96  per  cent.  Prof.  Mallet  has  found,  as  the 
result  of  numerous  experiments,  that  the  creatinin  is 
excreted    unchanged,    while    the    creatin     is    changed 


-     ANIMAL  FOODS;   MEAT.  197 

wholly  or  very  largely  to  creatinin,  and  consequently  he 
believes  these  two  substances  cannot  be  regarded  as 
sources  of  energy,  being  excreted  practically  without 
having  undergone  change.  The  influence  of  creatin 
in  the  system,  according  to  Konig,  is  to  stimulate  the 
nervous  system. 

The  average  composition  of  albumin  may  be  taken  as 
follows:  In  100  parts,  nitrogen  16,  carbon  54,  oxygen  22, 
hydrogen  7,  and  sulphur  i.  In  the  group  of  substances 
headed  by  gelatin  the  proportion  of  nitrogen  (=  18  per 
cent.)  to  carbon  is  greater,  and  these  substances  are  much 
less  nutritious  than  the  albuminates  proper. 

Diseases    Produced    by  Diseased    Meat AH    animals 

slaughtered  for  food  should  be  free  from  disease.  Cer- 
tain diseases  from  which  the  domestic  animals  suffer 
are  directly  communicable  to  man;  others  are  not  directly 
communicable  to  man,  but  the  flesh  of  the  animals  suf- 
fering from  them  is  unfit  for  food.  The  inspection 
should  be  made  both  before  and  after  slaughtering. 

The  diseases  of  cattle  which  render  their  flesh  unfit  for 
food  are  epidemic  pleuropneumonia,  foot-and-mouth 
disease,  Texas  cattle  fever,  cattle  plague,  anthrax,  actino- 
mycosis, and  tuberculosis.  Dropsical  conditions,  as  well 
as  all  inflammatory  conditions,  also  render  the  flesh  unfit 
for  food.  The  diseases  of  the  pig  which  render  the  flesh 
unfit  for  food  are  anthrax,  muco-enteritis,  hog-cholera, 
tuberculosis,  Cysticercus  cellulosa,  and  Trichinella  spi- 
ralis. 

Meat  Inspection. — Some  of  the  diseases  of  the  domestic 
animals  can  be  recognized  before  death,  but  most  of 
them  must  be  detected  by  post-mortem  examination, 
either  by  general  inspection  of  the  carcass  and  of  the 
organs  and  different  portions  of  the  body,  or  by  micro- 
scopic examination. 

The  general  inspection  includes  the  observation  of  the 
nature  and  the  quantity  of  fat,  the  color,  odor,  and  con- 
sistence of  the  muscles,  condition  of  the  bone-marrow. 


198  "  FOOD  AND  DIETING. 

and  the  condition  of  the  lungs,  Hver,  spleen,  kidneys, 
and  the  lymphatic  glands. 

There  should  not  be  an  excessive  amount  of  fat,  or 
else  the  proportion  of  proteid  matter  will  be  too  low;  it 
should  be  firm  and  not  too  yellow,  and  without  hemor- 
rhagic foci.  The  color  of  the  fat  will  vary  somewhat 
with  the  age,  breed,  and  color  of  the  animal,  and  the 
kind  of  food. 

The  muscles  should  be  firm  yet  elastic.  They  should 
be  tolerably  dry  and  have  a  pleasant  odor.  There  should 
be  no  lividity  on  cutting  across  some  of  the  muscles.  A 
purple  color  may  be  indicative  that  the  animal  has  not 
been  slaughtered,  or  that  it  suffered  from  some  acute 
disease.  There  should  be  a  marbled  appearance  from  the 
ramification  of  connective  tissue  and  fat  between  the 
muscular  bundles. 

The  bone-marrow  of  the  hind  legs  is  of  a  light  rosy- 
red  color,  and  remains  solid  for  about  twenty-four  hours 
after  death.  If  it  is  soft,  brownish,  or  with  dark  points, 
the  animal  may  have  been  sick,  or  putrefaction  may  be 
commencing.  The  marrow  of  the  fore  legs  is  somewhat 
softer  and  of  a  rose-red  color. 

The  internal  organs  should  be  carefully  inspected  for 
the  presence  of  tumors,  parasites,  or  suppuration.  The 
lungs  and  pleurae  will  usually  show  the  presence  of  tuber- 
culosis, through  the  deposition  of  tubercles.  Sometimes 
these  are  found  first  in  the  lymphatic  glands  of  the  mesen- 
tery and  mediastinum.. 

The  microscopic  examination  of  meat  is  directed  prin- 
cipally toward  the  detection  of  parasites,  such  as  the 
cysticercus,  psorospermia,  and  trichina.  The  cysticercus 
may  be  found  in  the  flesh  of  cattle  and  pigs;  the  psoro- 
spermia in  the  flesh  of  fish,  rabbits,  and  pigs ;  and  the 
trichinia  in  the  flesh  of  pigs.  A  power  of  from  25  to  50 
diameters  is  sufficient  to  detect  these  parasites  in  meat. 

Method  of  Meat  Inspection. — The  method  of  meat  in- 
spection, and  the  restrictions  placed  upon  the  sale  of  the 
meat  of  diseased  cattle,   differ  very  greatly  in  different 


ANIMAL  FOODS:  MEAT.  199 

countries.  For  instance,  Saxony  and  Bavaria,  in  Ger- 
many, Italy,  Russia,  and  Denmark  allow  the  sale  of  the 
meat  of  tubercular  animals  when  the  disease  has  not 
become  generalized,  providing  it  is  sold  with  the  under- 
standing that  it  is  derived  from  diseased  animals,  or  is  sold 
as  second-class  meat.  In  most  foreign  countries,  as  well 
as  in  the  United  States,  the  meat  of  tubercular  animals  is 
sold  without  any  declaration  as  to  its  nature  as  whole- 
some meat  when  the  disease  is  localized. 

In  the  United  States  the  inspection  of  meat  is  in 
charge  of  the  national  government.  Meat  inspectors  are 
stationed  at  the  slaughter-houses  of  all  large  cities,  and 
each  carcass  is  inspected  as  soon  as  slaughtered.  This 
system  of  inspection  should  be  extended  so  as  to  include 
towns  of  smaller  size,  because,  especially  in  the  West, 
three,  four,  or  more  small  slaughter-houses  are  clustered 
on  the  outskirts  of  small  towns,  and  each  may  become  a 
focus  for  the  dissemination  of  disease. 

Meat  intended  for  export  is  always  subjected  to  rigid 
inspection.  Edelmann  ^  states  that  pigs'  livers  imported 
into  Dresden  from  America  or  Denmark  frequently  con- 
tain trichinella.  But  in  the  year  1896  only  four  livers 
out  of  2023  were  found  to  be  infected,  and  in  each  case 
the  parasites  were  dead,  probably  owing  to  the  use  of 
antiseptics  to  preserve  the  meat.  All  pork  intended  for 
exportation  is  examined  microscopically  for  the  presence 
of  the  Trichinella  spiralis.  This  inspection  is  made  by 
the  Federal  authorities  at  the  slaughter-house.  Most  of 
this  work  is  done  in  Chicago.  In  most  cities  of  the 
United  States  the  meat  intended  for  local  consumption  is 
inspected  very  superficially  or  not  at  all. 

Ostertag^  mentions  the  following  points  as  forming  the 
foundation  upon  which  the  rules  governing  the  question 
of  meat  inspection  must  be  based: 

I.  The  erection  of  public  slaughter-houses  in  all  cities 
of  more  than  5000  inhabitants. 

1  Zeit.  Fleisch-  u.  Milch-Hyg.,  1898,  p.  64. 

2  Trans.  German   Veterinary  Council  for  1891. 


200  FOOD  AND  DIETING. 

2.  Compelling  the  butchers  to  kill  their  animals  in 
these  slaughter-houses,  and  to  discontinue  the  use  of 
private  slaughter-houses. 

3.  Professional  direction  of  the  slaughter-houses,  and 
the  inspection  of  all  animals  both  before  and  after  the 
slaughter. 

4.  The  provision  of  stalls  for  the  sale  of  inferior  but 
not  unhealthy  meat  (not  apt  to  cause  disease  in  man), 
such  as  meat  of  an  abnormal  color,  odor,  bloody  meat, 
and  that  from  sick  animals.  The  provision  of  a  cooking 
or  sterilizing  apparatus,  for  cooking  such  meat  as  might 
cruse  disease  if  consumed  raw,  but  would  be  harmless 
when  cooked  (meat  containing  cysticerci,  trichina,  and 
tubercle  bacilli). 

5.  The  total  destruction  of  those  animals  and  parts  of 
animals  which  are  condemned  as  unfit  for  food. 

6.  The  formation  of  a  co-operative  insurance  society 
for  the  purpose  of  recompensing  the  owners  of  condemned 
cattle.  It  is  best  that  this  society  should  be  conducted 
by  the  city  or  town,  in  order  that  the  losses  might  be 
regularly  distributed. 

It  seems  evident,  from  the  experiments  of  Woodhead 
and  others,  that  there  is  positive  danger  from  the  use  of 
meat  of  tubercular  animals  even  though  the  disease  has 
not  been  generalized.  The  point  which  seems  to  be 
entirely  overlooked,  and  to  which  a  great  deal  of  impor- 
tance should  be  attached,  is  that  when  the  disease  is 
localized  in  one  or  more  organs  there  is  great  danger  of 
infecting  the  entire  carcass  by  the  butcher's  knife  in  re- 
moving these  infected  organs.  Not  only  may  the  carcass 
containing  the  tubercular  nodules  become  infected  in  this 
manner,  but  the  infection  may  also  be  carried  on  the 
butcher's  knife  to  the  carcasses  of  other  animals  slaugh- 
tered by  him. 

Food=poisoning. — Several  types  of  food-poisoning  have 
been  recognized.  The  first  group  of  these  food-poison- 
ings to  be  considered  is  that  due  to  Bacillus  botulinus, 
an  anaerobic  organism  discovered  by  Van  Brmengem  in 


ANIMAL  FOODS;  MEAT.  20I 

1895.  This  bacillus  produces  a  highly  toxic  poison  in 
meat  which,  when  taken  into  the  system,  has  an  especial 
affinity  for  the  nervous  system,  and  hence  the  character 
of  the  symptoms  seen  in  poisoning  from  tainted  meat. 
Kemperer  has  found  that  it  is  possible  to  counteract 
these  symptoms,  at  least  in  part,  by  means  of  an  anti- 
toxin derived  from  the  blood  of  animals  immunized 
against  the  bacillus.  Experiments  have  shown  that  dogs 
are  immune  to  this  organism  even  when  fed  in  their  food 
in  pure  cultures. 

The  second  group  results  from  the  development  of  pu- 
trefactive bacteria  in  originally  wholesome  foods,  and  the 
organisms  encountered  most  frequently  belong  to  the 
proteus  group.  The  effects  produced  are  due  to  putre- 
factive substances — ptomaines — formed  as  the  result  of 
the  metabolic  action  of  the  bacteria. 

The  third  group  is  caused  by  bacteria  belonging  to  the 
hog  cholera  group.  Clinically,  the  cases  are  usually  char- 
acterized by  acute,  stormy  onset,  mostly  with  chills  and 
high  fever,  severe  and  sometimes  uncontrollable  vomit- 
ing, violent  diarrhea,  cramps  in  the  legs,  and  rapid  loss 
of  strength.  Occasionally  the  course  is  milder  and  more 
like  that  of  typhoid  fever.  Paratyphoid  bacilli  have  been 
isolated  from  the  organs  and  tissues  of  diseased  animals, 
and  it  is  clearly  established  that  under  certain  circum- 
stances animals  from  which  we  obtain  food  are  subject  to 
infection  with  paratyphoid  bacilli.  These  infections 
appear  to  occur  only  sporadically,  and  the  special  con- 
ditions necessary  for  their  development  are  not  yet  clearly 
understood. 

In  the  majority  of  cases  of  poisoning  due  to  para- 
typhoid bacilli  it  concerns  an  actual  infection  with  bacilli 
in  addition  to  intoxication  with  substances  derived 
from  them.  This  intoxication  probably  manifests  itself 
in  the  severe  symptoms  often  characteristic  of  the  begin- 
ning of  the  attack.  Paratyphoid  bacilli,  as  well  as  the 
Gartner  bacillus,  form  toxic  substances  that  are  able  to 
resist  high  temperatures  and  which  in  smaller  animals 


202  FOOD  AND  DIETING. 

cause  diarrhea  and  convulsions.  When  only  a  small 
number  of  bacilli  is  introduced,  it  is  thought  that  the 
milder  form  of  the  disease,  a  form  of  so-called  paratyphoid 
fever,  may  develop,  and  in  some  of  the  epidemics  both 
the  clinical  forms  have  been  observed.  lycntz,  who  has 
studied  200  cases  of  paratyphoid  infection,  saw  in  about 
40  per  cent,  the  typhoid-like  course,  while  in  the  others 
the  attack  began  suddenly  with  high  fever  and  chills.  It 
is  interesting  to  note  that  in  cases  of  paratyphoid  intoxi- 
cation herpes  of  the  lips  and  nose  is  relatively  common, 
and  there  may  be  roseola  in  large  spots  ;  there  are  rarely 
ulcers  in  the  intestines ;  occasionally  there  is  a  pro- 
nounced, often  hemorrhagic,  enteritis. 

Preservation  of  Meat. — Meat  can  be  preserved  in  its 
normal  state  in  cold  climates  for  a  week  or  more  with- 
out undergoing  any  change  detrimental  to  health.  In 
warm  climates  it  cannot  be  preserved  longer  than  a  day 
or  two  without  resorting  to  some  method  to  prevent  the 
action  of  the  bacteria  of  putrefaction.  The  methods  in 
common  use  for  this  purpose  are  desiccation,  sterilization 
by  heat,  refrigeration,  salting,  and  the  use  of  antiseptic 
substances, — that  is,  substances  which  prevent  the  de- 
velopment and  action  of  putrefactive  bacteria. 

Desiccation  takes  away  the  moisture  and  thus  prevents 
the  growth  of  bacteria.  In  some  exceptionally  dry  cli- 
mates desiccation  takes  place  on  simple  exposure  to 
the  air.  Ordinarily,  however,  the  desiccation  must  be 
brought  about  by  artificial  heat.  In  common  practice 
the  process  is  conducted  in  a  smoke-house,  where  the 
smoke  assists  in  preserving  the  meat. 

Sterilization  by  heat  is  commonly  resorted  to  in  the 
household  where  other  methods  of  preserving  are  not 
available.  This  method  is  also  employed  commercially, 
and  the  sterilized  meat  is  preserved  in  hermetically  sealed 
receptacles,  in  which  it  keeps  indefinitely.  The  so- 
called  "canned  meat"  used  for  the  United  States  army 
during  the  Spanish-American  war  is  a  form  of  preserved 


ANIMAL  FOODS;  MEAT.  203 

meat.     When  the  receptacle  is  once  opened,  the  meat 
soon  undergoes  decomposition. 

Salting  is  one  of  the  oldest  methods  of  preserving 
meat.  The  action  of  the  salt  is  to  remove  moisture,  to 
harden  the  muscle-fiber,  and  it  is  also  deterrent  to  bac- 
terial action,  as  the  putrefactive  organisms  are  unable  to 
develop  in  the  presence  of  large  quantities  of  salt. 

The  use  of  various  a?itiseptic  substances  for  the  preser- 
vation of  meat  is  of  recent  date.  Since  all  antiseptic 
substances  are  poisonous,  they  should  not  be  employed 
for  this  purpose.  Meat  that  has  been  preserved  by 
means  of  antiseptic  substances  is  not  only  poisonous  be- 
cause of  the  antiseptics  contained  in  it,  but  it  is  also 
objectionable  because  these  antiseptics  render  it  tough 
and  indigestible,  and  therefore  irritant  to  the  gastro- 
intestinal tract.  The  antiseptic  substances  employed  for 
this  purpose  are  boric,  benzoic,  and  salicylic  acids,  sodium 
sulphite,  and  formaldehyd.  All  these  substances  hinder 
the  process  of  digestion,  and  are  therefore  harmful. 

The  only  safe  and  rational  method  of  preserving  meat 
is  by  refrigeration.  In  this  way  meat  can  be  stored  for 
a  considerable  time  or  shipped  long  distances  without 
suffering  in  character  or  digestibility. 

Smoked,  salted,  and  sterilized  meats  are  far  more  diffi- 
cult to  digest,  besides  being  less  palatable  and  less  nutri- 
tious than  fresh  meat.  Meat  preserved  by  sterilization  is 
less  nutritious  and  less  palatable  than  fresh  meat,  and  it 
is  also  less  nutritious  because  it  is  overcooked. 

Detection  of  Meat  Preservatives. — The  Jorgensen  ^ 
method  of  estimating  boric  acid  in  meat  preservatives  is 
based  upon  the  fact  that  a  watery  solution  of  boric  acid, 
neutral  to  phenolphthalein,  after  being  treated  with  a 
sufficient  quantity  of  glycerin,  again  takes  on  an  acid 
reaction,  and  that  by  subsequent  titration  with  caustic 
alkali  solution  the  amount  of  boric  acid  can  be  estimated 
if  the  value  of  the  alkali  solution  has  been  carefully 
determined. 

^Abst.  in  Hyg.  Rundscltaii,  Bd.  x,  S.  744. 


204  FOOD  AND  DIETING. 

The  sample  of  meat  treated  with  known  amounts  of 
boric  acid  are  made  strongly  alkaline  with  caustic  soda 
solution,  and  then  extracted  for  several  hours  with  hot 
water.  The  filtrate  is  evaporated  to  dryness,  incinerated, 
and  the  ash  dissolved  in  sulphuric  acid.  This  solution  is 
gently  warmed  for  some  time  to  remove  the  carbon 
dioxid,  and,  after  cooling,  is  accurately  neutralized  to 
phenolphthalein. 

The  fluid,  about  50  c.c.  in  amount,  is  then  treated  with 

2S  C.C.  of  glycerin  and  titrated  with  —  NaHO  solution 

10 

without  regard  to  the  phosphates  that  may  be  precipi- 
tated; the  end-reaction  is  made  more  definite  by  the 
addition  of  ethyl  alcohol.  In  this  manner  94.94  per 
cent,  of  the  boric  acid  added  was  recovered. 

Borntrager  ^  makes  the  following  statements  with  regard 
to  the  use  of  sodium  sulphite  (NaaSOg)  as  a  meat  preserv- 
ative :  ' '  The  extensive  use  of  food  preservatives  is  not 
generally  recognized  by  the  physician.  The  continued 
use  of  food  substances  preserved  in  this  manner  is  detri- 
mental to  health. 

"When  sodium  sulphite  is  present  in  food  sulphurous 
acid  gas  is  liberated  in  the  stomach  through  the  action 
of  the  hydrochloric  acid  of  the  digestive  fluid,  and  this 
leads  to  strong  local  irritation.  The  salt  also  acts  in  the 
organism  as  a  free  acid. 

"After  eating  Frankfurt,  Vienna,  or  Bock  sausage, 
or  drinking  the  so-called  Rhine  or  Moselle  wines,  there 
was  eructation  of  sulphurous  acid  and  hydrogen  sulphid, 
with  pressure  and  discomfort  in  the  stomach,  and  head- 
ache, which  lasted  a  considerable  time." 

The  use  of  borax,  sodium  sulphite,  and  other  preserva^- 
tives  in  meat  produces  definite  trains  of  symptoms  and 
pathological  conditions,  especially  lesions  of  the  kidneys,  as 
the  result  of  the  attempts  at  elimination  of  these  poisons. 

Although  the  use  of  meat  preservatives  is  prohibited  by 
the  pure  food  laws  of  the  United  States,  there  is  reason 

^  Abst.  Uyg.  Rundschau,  Bd.  x.,  S.  743. 


ANIMAL  FOODS;  ME  A  T.  205 

to  believe  that  systematic  chemical  examinations  of  meats 
would  reveal  frequent  employment  of  these  substances. 
Unless  we  can  invoke  the  aid  of  national,  state,  and  muni- 
•  cipal  governments  in  inhibiting  the  use  of  preservatives 
of  this  character,  it  is  probable  that  the  influence  of  all 
other  hygienic  measures  which  tend  to  prolong  life  will  be 
nullified  because  of  the  greater  detriment  exerted  by  the 
constant  use  of  meats  containing  these  preservatives. 

Cooking. — The  value  of  meat  as  served  on  the  table  is 
influenced  to  a  considerable  extent  by  the  manner  in 
which  it  is  cooked.  The  object  of  cooking  meat  is  to 
render  it  more  easy  of  mastication  and  digestion,  and  to 
render  it  more  palatable.  It  also  serves  to  kill  any  para- 
sites present,  and  thus  prevents  infection. 

Of  the  different  methods  of  cooking  meat,  broiling  and 
roasting  are  the  best,  as  in  these  methods  the  juices  of 
the  meat  are  retained  as  much  as  possible.  In  boiling 
and  stewing  a  considerable  portion  of  the  juices  is  ex- 
tracted. Frying  in  oil  renders  the  meat  richer  in  fats, 
and  therefore  more  difficult  to  digest  than  when  roasted 
or  broiled. 

Effect  of  Light  and  Dark  Meats. — In  recent  years 
there  has  been  considerable  discussion  as  to  the  in- 
fluence of  dark  meats,  especially  in  cases  of  chronic 
parenchymatous  nephritis,  and  in  diseases  of  the  nervous 
system.  This  differentiation  between  light  and  dark 
meats  has  been  traced  back  to  the  time  of  Sydenham, 
who  allowed  his  neurasthenic  patients  the  light  meat  of 
calves,  chickens,  and  fish,  but  prohibited  the  use  of  beef, 
because  it  favored  the  production  of  nervous  disease. 
Later  it  was  prohibited  because  it  was  believed  to  favor 
the  production  of  uric  acid.  In  consequence  of  this  fact 
the  differentiation  between  light  and  dark  meats  began 
to  play  an  important  role  in  the  treatment  of  diseases  of 
the  kidneys.  In  recent  times  stomach  and  intestinal 
diseases,  acute  and  chronic  rheumatism,  and  the  func- 
tional neuroses  are  also  believed  to  be  influenced  unfav- 
orablv  bv  the  use  of  the  dark  meats. 


2o6  FOOD  AND  DIETING. 

In  the  treatment  of  kidney  diseases  the  prohibition  of 
dark  meats  is  based  upon  the  fact  that  these  meats  con- 
tain a  greater  proportion  of  nitrogenous  extractives,  and 
that  these  extractives  produce  irritation  of  the  kidneys 
when  eliminated,  or  in  deficient  action  of  the  kidneys 
they  accumulate  in  the  S3'stem  and  produce  toxic  effects. 
The  nitrogenous  extractives  of  meat  to  which  this  effect 
is  traced  are,  more  especially,  the  creatin  and  creatinin, 
xanthin,  leucin  and  tyrosin,  and  ptomains,  besides  other 
extractives.  Smoked  and  pickled  meats  contain  other 
irritating  products,  besides  those  contained  in  fresh 
meat,  and  are  therefore  far  more  injurious. 

The  trend  of  opinion  at  the  present  time  is  to  minimize 
the  differentiation.  Pabst  was  unable  to  determine  any 
appreciable  difference  in  the  amount  of  urine  excreted, 
and  the  proportion  of  albumin  eliminated,  with  a  milk 
diet,  a  diet  of  dark  meat,  white  meat,  or  a  mixed  diet. 

The  explanation  for  the  supposed  injurious  effects  of 
dark  meats  has  also  been  attributed  to  the  effect  of  the 
simultaneous  use  of  carbohydrates  (Kirk).  The  use  of 
dark  meats  with  the  exclusion  of  the  carbohydrates  is 
stated  to  be  of  decided  advantage  in  the  treatment  of 
neurasthenics.  While  there  is  some  clinical  evidence  as 
to  the  validity  of  this  assumption,  it  will  be  best  to  await 
more  extended  experience  before  abandoning  the  teach- 
ing of  Sydenham. 

Composition  of  Meat. — Lean  beef  is  composed  of 
about  76  per  cent,  of  water,  21.5  per  cent,  of  nitro- 
genous substances,  1.5  per  cent,  of  fat,  and  i  per  cent, 
of  salts.  The  composition  varies,  however,  in  the 
same  animal  according  to  the  part  from  which  it  is 
taken,  for  instance:  The  neck  contains  73.5  per  cent, 
of  water,  19.5  per  cent,  of  nitrogenous  substances,  5.8 
per  cent,  of  fat,  and  1.2  per  cent,  of  salts;  the  flank, 
63.4  per  cent,  of  water,  18.8  per  cent,  of  nitrogenous 
substances,  16.7  per  cent,  of  fat,  and  i.i  per  cent,  of 
salts;    the  shoulder,    50.5  per  cent,   of  water,    14.5  per 


COMPOSITION  OF  ME  A  T. 


207 


cent,  of  nitrogenous  substances,  34  per  cent,  of  fat,  and 
I  per  cent,  of  salts.  With  increase  in  fat  the  percentage 
of  water  decreases  ;  the  percentage  of  nitrogenous  sub- 
stance is,  however,  increased  very  little  by  the  fattening 
process.  The  percentage  of  water  is  also  greater  in  the 
flesh  of  young  animals  than  in  that  of  adult  animals. 

Veal. — Veal  is  usually  more  difficult  of  digestion  than 
beef.  Konig  attributes  this  to  the  fact  that  it  is  more 
tender  and  therefore  less  resistant  to  the  masticating 
process,  and  is,  consequently,  masticated  with  more  diffi- 
culty than  other  meat.  It  contains  a  greater  proportion 
of  water  than  beef.  Its  nutritive  value  is  dependent 
upon  the  age  of  the  calf  when  slaughtered,  the  younger 
it  is  the  more  watery  the  flesh,  and  the  lower  the  propor- 
tion of  nutritive  substances.  In  some  countries,  as  in 
the  United  States  and  Austria,  veal  is  not  permitted  to 
be  used  for  food  under  one  month  of  age. 


Composition  of  the  Flesh  of  Domestic  Animals} 


Ox 

Cow \ 

Calf I 

Sheep \ 

--- { 

Horse 


Condition. 


Per  cent. 


Water. 


Very  fat 
Medium 
Lean     . 

Fat  .  . 
Lean     . 

Fat  .  . 
Lean     . 

Fat  .  . 
Lean     . 

Fat  .  . 
Lean     . 

(Mean) 


S3.0S 
72.03 
73-67 


47.40 
72-57 


Nitrogenous 
substance. 


Fat.        Nitrogen-freej   ^^^ 
extractives. 


0.46 


0.46 


0.46 


0.92 

I 

14 

I 

18 

I 

07 

1 

32 

I 

33 

0 

50 

0 

93 

I 

33 

0 

72 

I 

10 

Mutton. — The  flesh  of  sheep  and  lambs  is  composed  of 
finer  muscular  bundles  than  beef,  and  is,  in  general, 
easily  digested. 


^Mitchell,  Flesh  Foods,  London,  1900,  p.  47. 


2o8 


FOOD  AND  DIETING. 


Relative  Compositiojt  of  Different  Kinds  of  Meat  (Kotiig). 


Ox,  fat 

Calf,  fat  (9  analyses)  . 
Lamb,  fat  (9  analyses) 
Pork,  fat  (5  analyses)  . 
Horse  (12  analyses).    . 

Chicken,  fat 

Duck,  wild 

Goose,  fat 

Herring  (2  analyses)  . 
Trout  (8  analyses)    .    . 


3 

In  dry  substance. 

3  C 

0  u 

°  s 

a  ■" 

u 

S)=« 

ho  > 

bn-^ 

bo 

Ik 

oa 

„. 

is  0 

M 

2 

^ 

iz; 

^i^ 

0! 

'& 

15 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

Per 

cent. 

cent. 

cent. 

cent. 

cent. 

cent. 

cent. 

cent. 

45-5 

14-5 

30.17 

3-9 

72-31 

18.8 

7-41 

0 

07 

1-33 

68.87 

26.04 

11.02 

53-31 

16.82 

28.61 

0-93 

35-59 

61.28 

5-70 

47.40 

14-54 

37-34 

0.72 

28.16 

70.44 

4-50 

74.27 

21.71 

2.55 

0 

46 

1. 01 

85.69- 

8.46 

13-71 

76.22 

18.48 

9-34 

I 

20 

0.91 

61.76 

31-19 

9.88 

70.8:2 

22.65 

3" 

2 

33 

1.09 

77-59 

10.62 

12.92 

38.02 

15-91 

45-59 

0.48 

38.02 

73-55 

4.H 

74.64 

14-55 

9-03 

1.78 

56.42 

35-^5 

9-°3 

79 -fa 

18.42 

0.53 

0 

46 

0.96 

90.59 

2.42 

14.50 

Pork. — The  nature  of  the  food-supply  influences  the 
character  of  the  flesh  of  pigs  to  an  important  extent, 
especially  with  regard  to  its  flavor  and  the  deposition  of 
the  fat.  Pork  is  more  difficult  of  digestion  than  the  meat 
of  any  of  the  other  domestic  animals. 

Poultry  and  Game. — The  flesh  of  birds  differs  from 
that  of  mammals  in  the  fact  that  the  fat  is  deposited  in 
the  muscular  tis.sue  to  only  a  limited  extent.  It  is  also 
of  a  more  delicate  flavor  than  that  of  mammals.  It  is 
easier  to  digest  than  the  flesh  of  mammals  and  is  there- 
fore frequently  recommended  for  invalids. 

Pisli. — The  flesh  of  most  fish  is  white  because  their 
blood  is  white,  though  some  have  red  blood.  It  is  rich 
in  water,  and  varies  in  its  fat  content,  both  quantitatively 
and  qualitatively.  The  flavor  of  the  flesh  is  dependent 
upon  the  different  character  of  the  fat  in  different  fish. 
The  structure  of  the  flesh  is  similar  to  that  of  mammals, 
and  is  equally  nutritious.  According  to  the  investiga- 
tions of  Atwater,  the  flesh  of  fish  is  as  readily  digestible 
as  beef.     There  are,  however,  individual  differences. 

Milk  and  Milk-products. — Cows'  Milk. — Cows'  milk 
forms  a  most  important  article  of  diet  in  the  United 
States.  It  is  of  the  greatest  importance,  therefore,  that 
the  milk  placed  on  the  market  should  be  as  pure  and 
wholesome  as  possible.     The  fact  that  milk  is  such  a 


MILK  AND  MILK-PRODUCTS.  209 

favorable  culture-medium  for  most  classes  of  bacteria 
makes  it  possible  for  it  to  become  the  carrier  of  disease- 
producing  organisms.  It  may  also  be  dangerous  because 
of  the  presence  of  disease-producing  bacteria  derived 
from  the  cow,  or  because  of  the  presence  and  growth  of 
non-pathogenic  forms.  If  the  milk  could  be  collected 
and  stored  in  such  a  manner  as  to  prevent  the  entrance 
of  bacteria,  it  would  keep  a  long  time ;  but  this  is  im- 
possible, because  it  is  frequently  contaminated  with  bac- 
teria in  the  milk-ducts  of  the  udder.  It  is  also  further 
contaminated  with  bacteria  derived  from  the  fur  and 
udder  of  the  cow,  the  hands  of  the  milker,  the  air  of  the 
stable  and  milk-house,  and  the  utensils  in  which  it  is 
collected  and  stored. 

Some  of  these  bacteria,  as  the  lactic-acid  group,  fer- 
ment the  lactose  and  produce  lactic  acid,  causing  the  milk 
to  turn  sour  and  the  casein  often  to  coagulate.  Other 
classes  of  bacteria  cause  the  milk  to  decompose,  with  the 
production  of  odors ;  these  are  the  putrefactive  organ- 
isms. It  has  been  found  that  storing  the  milk  in  an  ice- 
chest  for  several  days  inhibits  the  multiplication  of  the 
lactic-acid  group  of  bacteria,  but  does  not  inhibit  the 
multiplication  of  the  putrefactive  bacteria,  so  that  the 
milk  under  these  conditions  becomes  putrid  before  it 
turns  sour. 

Pure  and  wholesome  milk  can  be  obtained  only  from 
healthy  cows,  but  the  milk  of  healthy  cows  may  soon  be 
rendered  useless  through  carelessness  in  collecting  and 
storing.  The  precautions  necessary  for  the  marketing 
of  pure  and  wholesome  milk  are,  therefore,  far-reaching, 
numerous,  and  exacting.  These  precautionary  measures 
should  include  the  selection  of  healthy  cows ;  the  treat- 
ment and  housing  should  be  such  as  to  favor  the  mainte- 
nance of  their  health;  the  utmost  cleanliness  about  the 
stables  and  milk-house;  the  cleanliness  of  the  milker 
and  of  those  who  handle  and  market  the  milk;  the 
utmost  cleanliness  of  all  utensils  employed  in  collecting, 
storing,  and  marketing  milk. 

14 


2IO  FOOD  AND  DIETING. 

Diseases  Conveyed  through  Milk. — A  number  of  dis- 
eases may  be  conveyed  through  milk,  and  they  may  be 
derived  either  from  the  cow  yielding  the  milk  or  from 
those  who  come  in  contact  with  the  milk  in  collecting 
and  marketing  it.  The  diseases  that  may  be  conveyed 
directly  from  the  cow  are  tuberculosis  and  micro-organ- 
isms of  inflammatory  diseases,  such  as  the  Streptococcus 
and  Staphylococcus  pyogenes. 

While  the  positive  conveyance  of  tuberculosis  from 
the  domestic  animals  to  man  is  still  disputed  by  some, 
especially  that  of  bovine  tuberculosis  through  the  use  of 
the  milk  and  meat  of  tubercular  animals,  because  of 
slight  morphologic  and  biologic  differences  between  the 
bacillus  as  found  in  bovine  and  human  tuberculosis,  the 
trend  of  opinion  to-day  is  in  favor  of  regarding  the  milk 
of  all  tubercular  animals  as  dangerous  to  health.  The 
direct  transmission  of  bovine  tuberculosis  to  members  of 
the  human  family  is  infrequently  demonstrated,  because 
of  the  insidious  onset  of  the  disease  and  its  slow  progress; 
yet  there  are  some  cases  on  record  which  appear  beyond 
a  doubt  to  have  been  contracted  in  this  manner.  Leon- 
hart  reports  the  case  of  a  healthy  infant,  of  healthy  par- 
ents, which  was  weaned  and  put  on  cows'  milk.  The 
child  soon  died  of  tuberculosis  of  the  meninsfes,  intes- 
tines,  and  mesenteric  glands.  The  cow  from  which  the 
milk  was  derived  was  found  to  be  tuberculous.  Another 
child  fed  on  the  milk  of  the  same  cow  died,  at  about  the 
same  time,  from  tubercular  meningitis.  Sonntag  reports 
the  case  of  a  six  months'  old  infant,  of  healthy  parents, 
which  at  autopsy  showed  miliary  tuberculosis  of  the 
meninges.  It  was  fed  on  milk  derived  from  a  tubercular 
cow.  Hermsdorf  gives  3  instances  in  which  there  was 
extensive  intestinal  tuberculosis,  besides  general  affection 
of  other  organs.  One  had  taken  uncooked  milk  from  a 
tubercular  cow.  Demme  reports  the  case  of  a  four 
months'  old  infant  which  at  autopsy  showed  tuberculosis 
of  the  mesenteric  glands.  There  was  no  tuberculosis  in 
the  family  for  two  generations  on  either  side.     The  milk 


MILK  AND  MILK-PROD UCTS.  211 

came  from  a  cow  with  general  tuberculosis.  Bollinger 
cites  Stang's  case  of  a  boy  of  five  years,  who  sickened 
with  ascites  and  enlarged  glands  in  the  abdomen.  At 
autopsy  the  chief  lesion  was  tuberculosis  of  the  abdomi- 
nal lymphatics,  but  there  was  also  tuberculosis  of  the 
serous  membranes  and  of  the  lungs.  There  was  no 
tuberculosis  in  the  family  for  two  generations.  The  child 
had  for  years  been  in  the  habit  of  drinking  milk  warm 
from  a  cow,  which,  growing  thin  before  the  boy  died, 
was  killed,  and  found  to  be  tubercular. 

Holt  reports  on  1045  consecutive  autopsies  from  the 
records  of  the  New  York  Infant  Asylum  and  Babies' 
Hospital — 10  per  cent,  of  which  were  found  to  be  tuber- 
culous. In  the  latter  institution,  which  receives  only 
sick  children,  the  percentage  was  higher. 

To  guard  against  the  dangers  of  infection  through  the 
use  of  milk  from  tubercular  cows  the  thorough  inspec- 
tion of  all  cows  kept  for  breeding  purposes,  or  whose 
milk  is  offered  for  general  consumption,  should  be  in- 
sisted upon.  The  most  reliable  and  ready  method  known 
to-day,  by  means  of  which  we  can  detect  the  disease,  even 
in  its  incipient  stage,  is  the  tuberculin  test.  This  test  is 
now  employed  in  many  States  and  in  many  foreign 
countries,  and,  if  the  tuberculin  has  been  prepared  by 
competent  bacteriologists,  it  is  believed  to  be  without 
detrimental  effects  on  healthy  animals. 

Among  the  laws  enacted  to  arrest  the  spread  of  tuber- 
culosis among  cattle,  and  from  cattle  to  man,  may  be 
mentioned  the  tuberculin  law  of  Denmark,  of  1893, 
which  makes  regulations  for  the  exclusion  from  commerce 
of  all  animals  apparently  tubercular,  as  well  as  for  the 
pasturing  of  such  animals  together  with  others.  It  also 
forbids  the  use  of  uninspected  meat  of  such  animals,  and 
also  the  use  of  milk  from  cows  suffering  from  tuberculo- 
sis of  the  udder.  In  this  country  several  States  have 
passed  laws  creating  sanitary  commissions  for  the  inspec- 
tion and  slaughtering  of  diseased  animals  upon  the 
voluntary  request  of  the  dairymen.     The  Act  of  May  21, 


212  FOOD  AND  DIETING. 

1895,  establishing  the  State  lyive  Stock  Sanitary  Board 
of  Pennsylvania,  is  a  law  of  this  nature.  The  law  of 
April  26,  1895,  enacted  by  the  legislature  of  Minnesota, 
will  no  doubt  have  more  salutary  effects,  and  seems  to  be 
more  directly  in  the  line  of  future  action.  This  law 
directs  that  the  city  council  of  any  city  may,  by  ordi- 
nance, provide  for  the  inspection  of  milk  dairies  and  of 
dairy  herds  kept  for  the  production  of  milk  within  its 
limits,  and  issue  licenses,  for  which  no  fee  shall  be 
charged,  for  the  sale  of  milk  within  its  limits,  and 
regulate  the  same,  and  may  authorize  and  empower  the 
board  of  health  to  enforce  all  laws  and  ordinances  relat- 
ing to  the  production  and  sale  of  milk,  and  the  inspection 
of  dairies  and  dairy  herds  producing  milk  for  sale  or  con- 
sumption within  such  city,  and  to  appoint  such  in- 
spectors, experts,  and  chemists  as  are  necessary  for  the 
proper  enforcement  of  such  laws  and  ordinances.  Under 
this  law  the  city  council  of  Minneapolis  passed,  June  14, 
1895,  and  approved  June  21,  1895,  an  ordinance  embody- 
ing all  the  features  contained  in  the  State  law.  The  city 
of  Port  Huron,  Michigan,  also  adopted  a  milk  ordi- 
nance, September  26,  1896,  to  regulate  and  control  the 
sale  of  milk  in  the  city,  in  which  the  licensing  of  all 
milk-dealers,  and  the  inspection  of  all  dairy  herds  and 
dairies  is  required. 

In  New  York  City  an  ordinance  was  passed,  in  1895, 
forbidding  the  sale  of  milk  within  the  city  without  a 
permit  from  the  department  of  health,  and  requiring  that 
all  wagons  used  for  the  transportation  or  delivery  of 
milk  should  likewise  have  wagon  permits.  Before  these 
permits  are  issued  the  holder  must  furnish  information 
as  to  the  source  from  which  the  milk  is  obtained,  the 
number  of  animals,  the  character  of  the  food-supply, 
and  the  sanitary  conditions  surrounding  the  dairy.  All 
milk  cows  in  the  city  have  been  subjected  to  the  tuber- 
culin-test, under  the  supervision  of  the  health  depart- 
ment, and  the  diseased  animals  killed.     It  is  also  proposed 


MILK  AND  MILK-PRODUCTS.  213 

to  require  similar  tests  to  be  applied  to  all  cows  whose 
milk  is  sent  to  the  city. 

Dr.  John  R.  Mohler,  Chief  of  the  Pathological  Divi- 
sion, Bureau  of  Animal  Industry,  investigated  the  "  In- 
fectiveness  of  Milk  of  Cows  which  have  reacted  to  the 
Tuberculin  Test,"  and  reached  the  following  conclu- 
sions : 

The  tubercle  bacillus  may  be  demonstrated  in  milk 
from  tuberculous  cows  when  the  udders  show  no  per- 
ceptible evidence  of  disease  either  macroscopically  or 
microscopically. 

The  bacillus  of  tuberculosis  may  be  excreted  from 
such  an  udder  in  sufficient  numbers  to  produce  infec- 
tion in  experimental  animals  both  by  ingestion  and 
inoculation. 

That  in  cows  suffering  from  tuberculosis  the  udders 
may  become  infected  at  any  moment. 

The  presence  of  tubercle  bacillus  in  the  milk  of  tuber- 
culous cows  is  not  constant,  but  varies  from  day  to  day. 

Cows  secreting  virulent  milk  may  be  affected  with 
tuberculosis  to  a  degree  that  can  be  detected  only  by 
the  tuberculin  test.  Physical  examination  or  the  general 
appearance  of  the  animal  does  not  always  reveal  the 
disease. 

The  milk  of  all  cows  which  have  reacted  to  the  tuber- 
culin test  should  be  considered  as  suspicious,  and  should 
be  subjected  to  sterilization  before  using. 

Still  better,  tuberculous  cows  should  not  be  used  for 
general  dairy  purposes. 

Beck,  of  Berlin,  reported  on  an  investigation  of 
56  samples  of  market  milk  as  to  the  presence  of  patho- 
genic bacteria  in  such  milk.  He  found  tubercle  baciUi 
in  30.3  per  cent,  of  the  samples,  and  streptococci  in 
62.3  per  cent.  These  streptococci  were  pathogenic 
for  guinea-pigs  when  injected  intraperitoneally,  the  ani- 
mals dying  in  from  three  to  four  days  from  a  purulent 
peritonitis.  The  peritoneal  exudate  usually  contained 
the  streptococci  in  pure  cultures.     Mice  were  killed  in 


214  FOOD  AND  DIETING. 

about  twenty-four  hours  by  subcutaneous  and  intraperi- 
toneal injections  of  small  amounts  of  a  bouillon  culture 
of  the  streptococci,  with  symptoms  of  general  infection. 
Rabbits  died  in  two  or  three  days  after  intravenous  injec- 
tions of  a  few  drops  of  a  bouillon  culture;  in  some  in- 
stances serous,  purulent  exudates  into  the  joints  were 
observed.  A  fresh  culture  rubbed  into  the  skin  of  the 
rabbit's  ear  was  productive  of  an  erysipelatous  inflamma- 
tion of  the  entire  ear,  with  considerable  fever,  though  all 
of  these  animals  recovered.  The  injection  of  i  to  3.5 
cubic  centim.eters  of  a  fresh  bouillon  culture  into  the 
stomach  of  guinea-pigs  resulted  in  the  production  of 
severe  diarrhea,  some  of  the  animals  dying  of  enteritis. 
On  post-mortem  examination  of  these  animals  the  mucous 
membrane  of  the  intestine  was  found  to  be  markedly  red- 
dened, showing  ecchymoses,  and  the  fluid  contents  of  the 
intestine  contained  numerous  streptococci. 

Beck  believes  these  streptococci  to  be  closely  related 
to  those  found  by  Escherich  in  the  enteritis  of  infants. 
He  states  that  Romme  also  believes  in  the  danger  of 
infantile  enteritis  from  these  streptococci. 

The  use  of  milk  derived  from  cows  suffering  from  in- 
flammatory disease  of  the  milk-ducts  is  undoubtedly  pro- 
ductive of  inflammatory  conditions  of  the  gastro-intesti- 
nal  tract,  especially  in  infants.  The  cases  of  fatal  strep- 
tococcus enteritis  reported  by  Hirsch  and  Libbert  appear 
to  have  been  cases  of  this  kind.  Booker  is  also  of  the 
opinion  that  gastro-enteritis  is  not  infrequently  produced 
in  this  manner. 

Of  the  diseases  conveyed  in  milk,  aside  from  those 
derived  from  the  cows  themselves,  may  be  mentioned 
typhoid  fever,  cholera,  diphtheria,  and  scarlet  fever. 
These  diseases  are  not  produced  by  infection  derived 
from  the  cows,  but  by  contamination  of  the  milk  with 
polluted  water,  or  by  means  of  flies,  and  by  means  of 
infected  hands  and  clothing  of  the  milkers  or  those  em- 
ployed in  collecting  and  marketing  the  milk. 

Typhoid  fever  and  cholera  may  be  conveyed  through 


MILK  AND  MILK- PRO  DUCTS.  215 

milk  in  very  much  the  same  manner.  These  diseases 
are  most  frequently  conveyed  through  impure  drinking- 
water,  but  when  the  milking  utensils  are  washed  in  pol- 
luted water,  or  the  milk  is  diluted  with  water  containing 
the  typhoid  and  cholera  organisms,  the  diseases  may  be 
conveyed  in  this  manner.  Again,  flies  and  other  insects 
are  no  doubt  frequently  concerned  in  conveying  these 
diseases  by  coming  in  contact  with  the  fresh  evacuations 
of  patients  suffering  therefrom,  and  then  subsequently 
infecting  milk.  For  these  reasons  the  storing  of  milk  in 
such  a  manner  as  to  prevent  the  possibility  of  this  mode 
of  infection  is  of  the  greatest  importance. 

Diphtheria  and  scarlet  fever  may  be  conveyed  in  milk; 
and  a  number  of  epidemics  of  these  diseases  have  been 
traced  to  their  source  in  contaminated  milk.  The  most 
common  mode  of  contamination  is  through  the  infected 
hands  of  milkers  and  those  handling  the  milk.  The 
most  rigid  care  should  be  exercised  to  avoid  the  dissemi- 
nation of  these  diseases  in  this  manner.  No  one  suffer- 
ing from  these  diseases,  nor  any  one  coming  in  contact 
with  those  suffering  from  them,  should  be  allowed  to 
milk  or  handle  any  milk  that  is  intended  for  general 
consumption.  There  is  no  evidence  at  hand  to  substan- 
tiate the  belief  that  cattle  suffer  from  either  of  these  dis- 
eases. The  milk  is  usually  contaminated  by  the  family 
of  the  dairyman,  or  others  through  whose  hands  the 
milk  passes  on  its  way  to  the  consumer. 

Municipal  Control  of  the  Milk-supply. — In  order  to 
make  it  possible  for  the  poorer  classes  to  obtain  a  milk- 
supply  that  is  free  from  danger,  it  is  necessary  for  munici- 
palities to  institute  certain  regulations  to  control  the 
marketing  of  milk.  This  is  especially  necessary  on 
account  of  the  relation  of  the  milk-supply  to  the  high 
infantile  mortality.  There  should  be  direct  supervision 
of  the  dairies  and  their  surroundings.  This  should 
include  an  investigation  and  repeated  inspection  of  the 
health  of  the  herd,  the  nature  of  their  food-supph-,  the 
purity  of  the  water  on  the  farm,  and  the  general  sanitary- 


2l6  FOOD  AND  DIETING. 

conditions  on  the  farm.  All  the  milk-dealers  in  the  city 
should  be  licensed,  and  their  wagons  distinctly  marked 
so  as  to  indicate  the  name  of  the  dealer  and  the  source 
of  the  milk.  Especial  importance  should  be  attached  to 
the  sale  of  milk  in  stores  and  the  sanitary  precautions 
required  in  storing  milk.  The  use  of  all  preservatives 
must  be  strictly  prohibited  on  account  of  their  detri- 
mental influence  on  health. 

New  Milk  Law  of  Philadelphia. — The  efforts  to  im- 
prove the  milk  supply  of  Philadelphia  have  led  to  the 
appointment  of  a  commission  which,  in  its  report,  makes 
numerous  recommendations  concerning  the  collection 
and  distribution  of  milk.  The  commission  recommended 
that  the  milk  should  reach  the  city  at  a  temperature  not 
exceeding  50°  F.  This  regulation,  if  enforced,  will  pre- 
vent the  enormous  multiplication  of  bacteria  in  milk  in 
transportation  to  the  city. 

Production  of  Wholesome  Milk — The  production  of 
clean,  wholesome  milk  requires  attention  to  the  health 
and  cleanliness  of  the  persons  milking  the  cows  and 
handling  the  milk  ;  to  health,  stabling,  feeding,  and  gen- 
eral care  of  the  cows ;  to  the  cleanliness  and  care  of  the 
utensils  in  which  the  milk  is  collected,  stored,  and  mar- 
keted ;  and  to  care  with  which  the  milk  is  handled  in  the 
household. 

No  person  who  is  suffering  from  any  of  the  infectious 
diseases,  or  who  comes  in  contact  with  such  persons, 
should  be  allowed  to  handle  the  milk  or  milking  uten- 
sils. Persons  suffering  from  acute  or  chronic  catarrhal 
affections  of  the  respiratory  system,  from  tuberculosis,  or 
who  have  recently  recovered  from  typhoid  fever, dysentery, 
cholera,  scarlet  fever,  measles,  diphtheria,  or  small-pox 
should  be  allowed  about  the  dairy.  Persons  attending 
patients  suffering  from  any  of  the  acute  infectious  dis- 
eases should  also  be  excluded  from  the  dairy. 

Rigid  cleanliness  of  body  and  clothing  of  all  attend- 
ants about  the  stables  and  dairies,  or  engaged  in  handling 
the  milk,  is  essential  to  the  production  of  wholesome  milk. 


MILK  AND  MILK-PRODUCTS.  217 

A  number  of  epidemics  of  typhoid  fever  have  been 
traced  to  persons  who  were  typhoid  bacilhis  carriers  that 
were  engaged  about  dairies,  on  milk  wagons,  or  in  shops 
where  milk  is  disposed  from  large  containers. 

The  stables  in  which  dairy  cattle  are  kept  should  be 
but  one  story  in  height  and  well  ventilated.  The  floors 
should  be  of  impervious  material,  preferably  cement,  so 
as  to  prevent  the  accumulation  of  filth  to  undergo  de- 
composition. The  floors  should  consist  of  absorbent  ma- 
terial, which  gives  rise  to  the  least  amount  of  dust.  The 
manure  should  be  removed  twice  a  day  and  stored  at 
some  distance  from  the  stable.  The  walls  of  the  stable 
should  be  whitewashed  once  or  twice  a  year.  The  cows 
must  be  healthy  stock.  Special  care  should  be  taken  to 
exclude  all  tuberculous  animals.  The  herd  should  be 
tested  twice  a  year  by  a  skilled  veterinarian.  All  animals 
reacting  to  the  tuberculin  test  should  be  removed  from 
the  dairy.  Cows  sufifering  from  infection  of  the  udder, 
or  other  infectious  disease,  should  also  be  removed  until 
such  time  as  they  may  have  recovered  from  the  infection. 
No  cows  should  be  added  to  the  dairy  until  it  has  been 
demonstrated  that  they  are  in  a  sound  and  healthy  con- 
dition. 

The  entire  body  of  the  cow  should  be  cleaned  each 
day,  and  just  before  milking  the  udder  and  flanks  should 
be  brushed  and  wiped  with  a  clean  damp  cloth. 

The  milker  should  be  clothed  with  clean  clothes,  wash 
his  hands  before  milking  each  cow,  and  milk  with  dry 
hands.     Wet-milking  should  be  rigidly  prohibited. 

All  the  utensils  used  in  collecting,  cooling,  and  stor- 
ing the  milk  should  be  cleaned  and  sterilized  before  they 
are  used.  The  milk  should  be  bottled  as  quickly  as  pos- 
sible, and  the  bottles  packed  in  ice  or  placed  in  cold 
storage  until  shipment  is  made. 

When  the  milk  reaches  the  consumer  it  should  be 
placed  in  a  clean  refrigerator  to  keep  it  cold,  and  it 
should  be  removed  from  the  bottle  at  the  time  it  is  to  be 


2i8  FOOD  AND  DIETING. 

used.  Milk  that  has  been  removed  from  the  bottle 
should  not  be  returned  when  it  is  not  used  at  once. 

Pasteurization  of  Milk. — Most  of  the  milk  shipped  to 
the  larger  cities  is  sent  in  bulk  from  long  distances  and 
reaches  the  consumer  with  large  numbers  of  bacteria. 
Frequently  milk  is  encountered  containing  millions  of 
bacteria  of  various  sorts.  Because  this  milk  does  not 
keep  many  hours  in  hot  weather,  and  especially  because 
it  frequently  contains  infectious  bacteria,  it  has  been 
generally  advocated  that  the  safest  procedure  is  to  sub- 
ject it  to  heat — that  is,  pasteurize  it. 

A  number  of  varieties  of  pasteurizing  machines  are  on 
the  market ;  but  the  processes  by  which  pasteurization  is 
accomplished  may  be  divided  into  two  principal  types — 
the  flash  process  and  the  holding  process.  In  the  flash 
process  the  milk  passes  through  the  apparatus,  and  in  one 
part  of  its  course  it  is  heated  momentarily  to  the  boiling- 
point  and  is  quickly  cooled  by  passing  through  a  com- 
partment cooled  by  ice  or  brine.  In  the  holding  process 
the  milk  is  quickly  heated  up  to  60°  to  65°  C. ,  and 
held  at  that  temperature  for  twenty  to  thirty  minutes. 
The  latter  process  is  far  more  certain  of  killing  all  dis- 
ease-producing bacteria. 

Pasteurized  milk,  where  the  process  is  conducted  in  a 
proper  manner,  is  a  safe  milk.  If  the  pasteurization  is 
carried  out  in  the  bottles  in  which  the  milk  is  delivered 
to  the  consumer,  there  is  no  danger  of  conveying  any  of 
the  infectious  diseases  through  the  milk-supply.  Pas- 
teurized milk  is  just  as  wholesome  as  raw  milk,  though 
it  does  not  keep  as  long  as  a  clean  raw  milk,  because  not 
all  the  bacteria  are  killed  during  the  process  of  pasteuri- 
zation. Any  bacterial  spores  that  are  in  the  milk  may, 
and  usually  do,  survive  the  pasteurization,  and  unless 
the  milk  is  kept  at  a  low  temperature  the  spores  germi- 
nate and  multiply  rapidly,  producing*  objectionable  and 
even  harmful  metabolic  products. 

Certified  Milk. — Certified  milk  is  produced  in  many 
parts  of  the  country.     It  consists  of  milk  of  dairies  that 


MILK  AND  MILK-PRODUCTS.  219 

are  conducted  on  the  most  approved  methods.     All  the 

cows  are  tested  by  a  veterinarian  in  the  employ  of  the 
local  milk  commission.  The  arrangements  of  the  stables 
and  milk  honse  are  such  as  to  make  it  possible  to  collect 
the  milk  in  such  a  manner  as  to  exclude  most  of  the  ex- 
traneous bacteria,  and  the  milk  is  bottled  as  quickly  as 
possible  and  served  to  the  consumer  in  these  containers. 
The  chemical  and  bacteriologic  composition  of  the  milk 
is  tested  by  experts  in  the  employ  of  the  milk  commis- 
sion. The  inspection  and  analytical  work  is  paid  by  the 
producers,  and  the  milk  is  sold  at  a  higher  price  than 
ordinary  milk. 

Certified  milk  is  used  for  infant  feeding  and  for  sick 
and  convalescing  patients.  The  bacterial  content  of  cer- 
tified milk  is  generally  less  than  10,000,  and  frequently 
only  several  hundred  bacteria  are  found  in  each  cubic 
centimeter,  and  these  are  largely  the  ordinary  lactic-acid 
bacteria  which  are  found  in  all  normal  milk. 

Butter. — Butter  serves  as  an  important  source  of  fat  in 
the  food  of  most  people.  It  is  very  palatable  to  most 
persons,  and  it  is  easily  digested  when  fresh  and  pure. 
When  kept  for  some  time  butter  becomes  rancid — that  is, 
the  fat  becomes  changed  through  the  action  of  bacteria 
contained  in  the  butter,  and  in  this  condition  it  is  more 
difficult  to  digest. 

Butter  may  be  injurious  to  health  in  two  ways :  It  may 
contain  the  specific  micro-organisms  of  certain  diseases, 
as  the  typhoid  bacillus  or  the  Bacillus  tuberculosis,  or 
the  presence  of  other  fats  of  animal  or  vegetable  origin. 
The  typhoid  bacillus  may  be  present  in  butter  through 
the  use  of  polluted  water  in  washing  the  utensils  used  in 
the  collection  and  storing  of  the  milk,  or  in  making  the 
butter.  The  Bacillus  tuberculosis  may  be  derived  from 
the  cows  from  which  the  milk  is  obtained.  Virulent 
tubercle,  bacilli  have  been  found  a  number  of  times  in 
butter  made  from  the  milk  of  tubercular  cows. 

The  addition  of  other  fatty  substances  to  butter,  or  the 
substitution  of  these  fats  for  butter,  under  the  names  of 


220  FOOD  AND  DIETING. 

butterin  and  oleomargarin,  is  now  prohibitd  bey  law, 
though  it  is  by  no  means  infrequent  even  at  the  present 
time.  These  fats  are  usually  more  difficult  of  digestion, 
aside  from  the  fact  that  they  are  fraudulent  substitutes 
for  a  more  costly  article  of  diet.  If  fats  derived  from 
diseased  animals  are  added  to  butter,  the  bacteria  con- 
tained in  these  may  be  a  source  of  danger  to  the  con- 
sumer. 

Cheese. — The  high  nutritive  value  of  cheese  and  its 
cheapness  make  it  an  important  article  of  food,  espe- 
cially for  the  poorer  classes. 

Cheese  may  be  injurious  to  health  on  account  of  the 
presence  of  tubercle  bacilli  when  the  milk  is  derived 
from  tubercular  cows,  though  it  is  claimed  these  organ- 
isms cannot  live  in  cheese  for  more  than  fourteen  days. 
The  typhoid  bacillus  and  cholera  organism  die  after  a 
very  few  days.  Cheese  may  also  be  injurious  to  health 
because  of  the  presence  of  poisonous  products  of  non- 
pathogenic bacteria  of  certain  species.  This  poisonous 
substance  is  of  the  nature  of  a  ptomain.  It  has  been 
extensively  studied  by  Vaughan,  who  has  called  it  tyro- 
toxicon.  This  form  of  poisoning  by  cheese  is  not  infre- 
quent. It  may  also  occur  in  ice-cream,  and  in  milk 
under  certain  circumstances.  It  is  accompanied  by 
grave  gastro-intestinal  disturbances  and  marked  nervous 
depression. 

Eggs  as  Food. — Bggs  are  used  as  food  in  very  large 
quantities,  and  their  use  as  a  food  has  become  a  question 
of  unusual  importance  in  recent  years  because  of  the  in- 
creasing demands  for  fresh  eggs  in  feeding  tuberculous 
individuals.  Bggs  derived  from  healthy  hens  are  occa- 
sionally contaminated  with  fecal  bacteria.  Hens  suffer- 
ing from  chronic  bacillary  infection  of  the  oviduct  yield 
eggs  that  appear  normal,  but  which  may  contain  con- 
siderable numbers  of  bacteria. 

Eggs  that  have  been  kept  in  cold  storage  for  a  time  are 
in  daneer  of  the  invasion  of  bacteria  from  the  exterior. 


VEGETABLE  FOODS. 


221 


Under  these  circumstance  the  eggs  may  be  highly  in- 
jurious to  the  health  of  the  consumer.  The  danger  of 
the  invasion  of  the  interior  of  the  ^^^  by  bacteria  is  still 
greater  when  the  eggs  are  moist.  When  the  shell  is 
cracked,  bacteria  enter  at  once  and  produce  alterations 
which,  in  a  short  time,  render  the  egg  putrid. 

Vegetable  Foods. — The  vegetable  foods  exceed  in 
number  and  form  those  derived  from  the  animal  king- 
dom. They  differ  from  the  animal  foods  principally  in 
the  form  in  which  the  nutritive  substances  (nitrogenous 
matter  and  fat)  occur,  and  in  the  presence  of  starch,  gums, 
sugars,  and  other  nitrogen-free  extractives  which  do  not 
occur  in  animal  foods.  These  latter  substances  con- 
tained in  vegetable  foods  take  the  place,  in  part,  of  the 
fats  in  animal  foods.  The  various  forms  of  sugar  found 
in  vegetable  foods,  as  glucose,  saccharose,  mannose,  etc., 
take  the  place  of  the  lactose  and  inosit  of  animal  foods. 
Another  nitrogen-free  substance  present  in  vegetable 
foods  which  is  not  found  in  animal  foods  is  cellulose, 
which  is  partly  digested,  and  in  part  serves  other  useful 
purposes  in  foods. 

The  nitrogenous  substances  contained  in  vegetable 
foods  are  vegetable  albumin  and  casein,  gluten,  nuclein, 
besides  other  nitrogenous  substances,  as  asparagin,  leu- 
cin,  amygdalin,  allantoin,  lecithin,  etc. 

The  mineral  substances  contained  in  vegetable  foods 
are  qualitatively  the  same  as  those  contained  in  animal 
foods. 


Composition  of  the  Cereals. 


(^         ,                   No.  of 
C^^^^'-               analyses. 

Nitrogenous 
substances. 

Fat. 

Nitrogen-    1   ,-,  ,, 

Ash. 

Nitro- 
gen. 

Wheat  .... 
Rye,  winter     . 
Barley  .... 

Oats 

Corn,  flint     .    . 
Rice 

Per  ct. 

1358             13-89 
173              12.48 
766             11.24 

377          12.13 
80          11.74 
10            7.C0 

Perct. 
2.20 
1.77 

1-93 
4-99 
4.78 
2.00 

Per  ct. 

79-75 
81.04 

77.24 

66.41 

79.20 
84.76 

Per  ct. 
2.19 
1.78 

4-95 

10.58 

1.67 

4.00 

Per  ct. 

1-97 
2.06 
2.42 

329 
1.40 
1. 16 

Per  ct. 
2.22 
2.00 
1.79 
1.94 
1.88 
1. 12 

222 


FOOD  AND  DIETING. 


CoTfiposition  of  the  LeguminoscB. 


No.  of 
analyses. 

Nitrogenous 
substances. 

Fat. 

Nitrogen- 
free  extract- 
ives. 

Cellu- 
lose. 

Ash. 

Nitro- 
gen. 

Beans    .... 
Peas 

63 

72 

Per  ct. 
29.26 
26.39 

Per  ct. 
1.68 

1-39 

Per  ct. 
55.86 
61.21 

Pej-  ct. 
8.06 
5.68 

Per  ct. 
313 

2.68 

Per  ct. 
4.68 
4-30 

The  high  protein  content  of  the  legumes  makes  these 
a  valuable  source  of  nitrogen.  They  are  comparatively 
low  in  price,  and  are  therefore  at  the  command  of 
families  in  the  poorest  circumstances.  Their  digestibility 
and  flavor  are  dependent  largely  upon  the  method  of 
preparation.  When  used  in  excessive  amounts  they  give 
rise  to  flatulency,  and  hence  should  always  be  combined 
with  other  articles  of  food. 

The  proportion  of  water  in  vegetable  foods  varies 
greatly,  ranging  from  about  90  per  cent,  in  beets  and 
turnips,  to  as  low  as  10  per  cent,  in  some  kinds  of  flour. 
In  general,  the  dry  seeds,  as  wheat,  corn,  beans,  and  dif- 
ferent kinds  of  flour,  contain  about  one-eighth  part  water 
and  about  seven-eighths  parts  nutrients.  Beans  and  peas 
contain  the  largest  proportions  of  proteid  matter,  and 
cornmeal,  potatoes,  rice,  turnips,  and  beets  the  least.  Of 
the  cereals,  wheat  is  the  richest  in  proteid  material. 
Wheat  bread  differs  from  wheat  flour  principally  in  the 
greater  proportion  of  water  present. 


Comparison 

of  Flour  and  Bread  (Atwater). 

Water. 

Nutri- 
ents. 

Proteid 
matter. 

Fat. 

Carbo- 
hydrates. 

Mineral 
matter. 

Fuel  value 
of  I  gram. 

Wheat  flour    .    . 
Baker's  bread  .  . 

Per  ct. 
12.00 
32.00 

Per  ct. 
88.00 
68.00 

Per  ct. 

12.00 

9.00 

Per  ct. 
1. 00 
2.00 

Per  ct. 
74.00 
56.00 

Per  ct. 
1. 00 
1. 00 

Calories. 
3.616 

2.866 

Bread. — In  bread-making  the  changes  brought  about 
by  the  process  are  twofold.  The  carbon  dioxid  gener- 
ated by  the  yeast,  or  forced  into  the  dough,  causes  it  to  be 
lio^ht  and  filled  with  small  cavities.      If  the  carbon  dioxid 


BREAD.  223 

is  generated  by  the  fermentative  action  of  the  yeast  plant, 
the  sugar  present  is  converted  into  carbon  dioxid,  and  at 
the  same  time  a  little  lactic  and  butyric  acids  are  formed, 
besides  some  extractive  matter.  A  portion  of  the  starch 
is  also  converted  into  dextrin  and  sugar.  During  the 
process  of  baking  the  fermentative  action  of  the  yeast 
plant  is  arrested  and  a  portion  of  the  albumin  is  coagu- 
lated. In  bread  made  with  the  aid  of  baking-powders  or 
by  forcing  carbon  dioxid  into  the  dough  the  products  of 
fermentation  are  absent,  and  the  only  change  produced 
is  that  brought  about  by  the  heat  in  baking. 

Baking=powders. — There  are  three  classes  of  baking- 
powders  in  use,  the  one  class  deriving  its  carbon  dioxid 
from  sodium  or  ammonium  carbonate  through  the  action 
of  tartaric  acid.  These  are  frequently  called  "  cream-of- 
tartar"  baking-powders,  because  potassium  acid  tartrate 
is  used  to  act  upon  the  sodium  carbonate,  or  bicarbonate, 
to  generate  the  carbon  dioxid.  Another  class  of  baking- 
powders  differs  from  the  foregoing  in  the  use  of  phosphoric 
acid  ;  these  are  called  the  phosphatic  baking-powders. 
The  other  class  of  baking-powders  is  the  "alum"  bak- 
ing-powders, because  in  these  the  double  sulphate  of 
aluminum  and  sodium  is  generally  employed  to  act  upon 
the  carbonate  to  generate  the  carbon  dioxid.  This  class 
of  baking-powders  is  considered  injurious  to  health.  A 
great  deal  of  evidence  has  been  collected  by  a  committee 
of  the  United  States  Senate,  which  uniformly  condemns 
the  use  of  alum  baking-powders.  The  continued  use  of 
alum  is  injurious  to  health,  because  of  its  irritant  and 
astringent  action  in  the  alimentary  tract,  and  when  con- 
tinued for  a  long  time  it  impairs  nutrition.  The  alum 
interferes  with  the  secretion  of  the  gastric  juice,  and  has 
an  irritant  action  on  the  intestines,  and  in  time  leads  to 
constipation,  and  in  certain  instances  to  disease  of  the  kid- 
neys. The  alum  baking-powders  also  produce  a  heavier 
and  more  indigestible  bread  than  the  cream-of-tartar 
baking-powders.  The  use  of  alum  in  food,  in  any  form,' 
is  prohibited  in  England,  France,  and  Germany. 


224  FOOD  AND  DIETING. 

Preserved  Meats. — Meats  may  be  preserved  against 
decomposition  in  several  ways,  as  drying,  smoking,  salt- 
ing, canning,  and  the  use  of  low  temperatures. 

The  use  of  dried,  smoked,  and  salted  meats  can  be 
traced  back  many  years,  and  the  hygienic  significance 
of  these  food-products  is  well  known.  Canned  meats, 
when  the  canning  process  is  carried  out  properly  on 
fresh  meats,  are  valuable  food -prod nets. 

The  use  of  low  temperatures  (cold  storage)  for  the  pres- 
ervation of  meats  has  come  into  great  prominence  in 
recent  years.  When  meats  are  stored  after  they  have 
been  invaded  by  bacteria  these  food-products  may  prove 
dangerous  to  the  consumer.  This  is  also  the  case  with 
meats  that  are  stored  at  temperatures  that  do  not  inhibit 
bacterial  action.  Cold  storage  of  meats  should  receive 
the  most  careful  supervision  of  the  government. 

Preserved  Vegetable  Foods. — Vegetable  foods  may 
be  preserved  in  several  ways.  The  method  which  has 
long  been  in  use  is  that  of  drying.  This  method  is  still 
used  ver}'  generally  in  preserving  certain  kinds  of  food. 
The  modification  of  this  method  in  use  in  large  manu- 
factories consists  in  exposing  the  fruit  to  the  fumes  of 
burning  sulphur  in  a  special  apparatus.  The  fruit,  when 
contained  in  galvanized-iron  trays,  is  certain  to  take  up 
appreciable  amounts  of  zinc  oxid.  This  fact  has  led  to 
restriction  of  the  importation  of  American  dried  fruits 
into  foreign  countries.  The  substitution  of  wooden, 
tin,  or  aluminum  trays  will  obviate  the  danger  of  con- 
tamination with  zinc.  The  amount  of  zinc  formed  aver- 
ages about  lo  milligrams  for  every  loo  grams  of  the 
fruit.  While  this  amount  of  zinc  is  probably  harmless 
when  taken  occasionally,  yet  when  constantly  present  in 
food  may  produce  derangement  of  health  through  its 
irritant  effect. 

Another  method  of  preserving  vegetable  foods  is  by 
means  of  heat.  This  method  is  unobjectionable  where 
the  food  is  stored  in  containers  that  yield  no  poisonous 
substances.     The  preservation  of  vegetable  foods  in  tin 


FOOD  PRESER  VA  TI VES.  225 

cans  is  quite  common,  and  there  is  some  danger  of 
lead-poisoning  from  these  foods  on  account  of  the 
presence  of  lead  in  the  solder  employed  in  sealing  the 
cans.  This  is  especially  the  case  with  acid  foods  or 
foods  that  have  been  imperfectly  preserved  so  that  the 
putrefactive  organisms  are  not  all  destroyed.  In  such 
instances  there  is  danger  of  solution  of  the  lead  through 
the  action  of  bacterial  products  upon  the  solder. 

Application  of  low  temperatures  in  the  preservation 
of  vegetable  food-products  has  come  into  great  promi- 
nence in  recent  years  and  has  aided  in  the  conservation 
of  food-products  to  a  marked  degree.  When  vegetable 
foods  are  stored  at  proper  temperatures  no  harm  can 
result  from  the  use  of  such  foods. 

Vegetable  foods  may  also  be  preserved  by  the  addition  of 
antiseptic  substances^  so  as  to  prevent  the  growth  of  micro- 
organisms. The  antiseptics  most  commonly  employed 
are  benzoic  and  salicylic  acid  and  formaldehyd.  These 
substances  are  in  themselves  irritant  poisons  when  taken 
in  certain  amounts,  while  smaller  amounts  used  for  a  long 
time  are  positively  injurious,  because  of  the  irritant 
effect  produced  on  the  gastro-intestinal  tract,  and  the 
inhibiting  influence  which  they  produce  on  the  digestive 
processes.  They  are  also  injurious  through  the  action 
they  have  on  albuminous  food-substances,  in  that  they 
render  them  difficult  of  digestion.  The  use  of  all  pre- 
servatives of  this  class  should  be  strictly  prohibited  by 
law. 

Food  preservatives  have  been  investigated  by  Prof 
Bigelow,  of  the  Agricultural  Department  at  Washing- 
ton, who  finds  that  their  manufacture  has  become  a  dis- 
tinct line  of  business.  Out  of  67  samples  of  the  most 
common  preservatives  in  use,  each  of  which  was  ob- 
tained with  great  difiiculty  when  it  was  known  that  it 
was  wanted  for  a  chemical  analysis,  33  contained  borax 
or  boric  acid  ;  10  sodium,  potassium,  or  calcium  sulphite  ; 
8  salicylic  acid  or  its  sodium  compound  ;  7  benzoic  acid 
or  its  sodium  compound  ;  i  boric  acid  and  salicylic  acid  ; 

15 


226  FOOD  AND  DIETING. 

I  boric  acid  and  ammonium  fluorid ;  2  pyroligneous  acid ; 
and  I  /3-naphtol.  Prof.  Bigelow  holds  that  those  un- 
doubtedly injurious,  such  as  formaldehyd,  salicylic  acid, 
and  sulphites,  should  be  proscribed,  and  a  stringent  law 
enacted  to  control  the  use  of  the  less  harmful  ones. 

Nuts  and  Their  Uses  as  Food. — Nuts  are  a  very  con- 
centrated food,  even  more  so  than  cheese,  but  when  used 
at  regular  meals  they  are  well  assimilated  and  may  form 
a  part  of  a  well-balanced  diet.  Nuts  are  a  very  valuable 
source  of  protein  and  fat,  these  two  nutrients  being  the 
characteristic  constituents  of  the  more  common  nuts, 
of  which  the  walnut  and  cocoanut  may  be  taken  as 
types.  In  the  chestnut  carbohydrates  are  a  character- 
istic constituent.  It  is  undoubtedly  better  to  use  nuts  as 
a  part  of  the  regular  diet  than  as  a  condiment  or  to  sup- 
plement an  other^vise  hearty  meal.  Persons  who  use 
nuts  in  place  of  meat  should  not  depend  upon  them  as 
the  main  food-supply,  but  should  supplement  them  with 
more  bulky  foods  with  a  low  content  of  protein  and  fat. 
Nuts  may  be  classed  among  the  staple  foods,  and  not 
simply  as  food  accessories. 

Mineral  Food. — The  most  important  mineral  food  is 
sodium  chlorid.  It  plays  an  important  rdle  in  favor- 
ing the  secretion  of  the  digestive  fluids.  A  drop  of 
dilute  salt  solution  placed  upon  the  gastric  mucous 
membrane  of  an  animal  causes  a  pouring  out  of  gastric 
juice  by  the  glands  of  the  stomach.  When  taken  into 
the  mouth  it  causes  the  saliva  to  flow  freely.  Vegetable 
foods  are  somewhat  deficient  in  salts,  and  require  the 
addition  of  sodium  chlorid  to  make  up  this  deficiency,  as 
well  as  to  enhance  their  flavor  and  palatability.  The 
vegetable  foods  are  richer  in  potassium  salts,  and  these, 
combining  with  the  sodium  salts  of  the  body,  cause  an 
increased  excretion  of  the  latter;  this  action  being  com- 
pensated by  the  addition  of  sodium  chlorid  to  the  food. 
The  amount  of  sodium  chlorid  taken  during  a  year  in  a 
mixed  diet  ranges  from  5  to  7  kilograms. 

The  other  mineral  food-substances  contained  in  both 


BEVERAGES  AND  CONDIMENTS.  22/ 

vegetable  and  animal  food  are  calcium  and  potassium 

phosphate;  potassium,  calcium,  and-  sodium  carbonate; 
and  magnesium  phosphate.  All  of  these  mineral  sub- 
stances have  important  nutritive  functions  in  the  body, 
but  they  are  present  in  sufficient  quantities  in  mixed 
diets,    so  that  no  further  additions  are  required. 

Beverages  and  Condiments. — Beverages  may  be 
classed  as  alcoholic  and  non-alcoholic.  The  alcoholic 
beverages  differ  from  each  other  not  only  in  the  quantity 
of  alcohol  present,  but  also  with  regard  to  the  presence 
of  various  extractive  substances  and  the  amount  and 
character  of  the  mineral  constituents. 

Alcoholic  Beverages. — Physiologic  experiments  have 
demonstrated  that  the  alcoholic  beverages  may  be  regarded 
as  articles  of  food,  not  only  on  account  of  the  quantity  of 
alcohol  present,  but  also  on  account  of  the  extractives 
which  they  contain.  They  serve  to  stimulate  the  diges- 
tion, the  circulation,  and  the  nervous  system.  They  also 
diminish  the  oxidation  processes  of  the  body  and  lower 
the  temperature.  Small  amounts  of  alcohol  may  be 
taken  daily  in  the  food,  and,  according  to  Prof  At- 
water's  experiments,  these  small  amounts  are  oxidized 
in  the  system  and  are  therefore  a  source  of  energy. 

The  principal  objection  to  the  use  of  alcoholic  bever- 
ages is  the  fact  that  their  constant  use  tends  to  the 
acquirement  of  the  drink-habit.  The  constant  use  of 
large  amounts  of  alcohol  leads  to  grave  derangement  of 
health,  and  for  this  reason  the  use  of  alcoholic  beverages 
is  to  be  condemned,  except  under  special  conditions  in 
disease  where  such  a  stimulant  may  be  required. 

Non=alcoholic  Beverages — The  more  important  non- 
alcoholic beverages,  besides  water,  are  tea,  coffee,  and 
cocoa.  These  beverages  have  a  stimulating  effect  because 
of  the  presence  of  an  alkaloid  in  each — thein  in  tea, 
caflfein  in  coffee,  and  theobromin  in  cocoa.  Besides 
these  alkaloids  they  contain  various  extractive  substances 
and  volatile  oils,  to  which  they  o\ye  their  peculiar  aroma. 
These  beverages    have  no  nutritive  qualities   in    them- 


228  FOOD  AND  DIETING. 

selves,  but  the  addition  of  sugar  and  milk  makes  them 
nutritious.  Their  principal  effect  is  one  of  stimulation. 
They  are  used  largely  as  convenient  modes  of  admin- 
istering water  with  the  food. 

The  chief  hygienic  interest  of  these  beverages  is  in 
the  effects  produced  by  excessive  usage.  The  effects 
produced  are  most  commonly  insomnia,  nervous  irrita- 
bility, indigestion,  and  palpitation  of  the  heart. 

Consumption  of  Fluids. —  The  American  Grocer  has 
been  collecting  statistics  concerning  the  home  consump- 
tion of  beverages,  excepting  water  and  soda-fountain 
products,  for  the  year  1900.  According  to  this  authority, 
the  amount  spent  was  ;^t, 228,674,925,  in  the  following 
proportions: 

Alcoholic  drinks $1,059,563,787 

Coffee 125,798,530 

Tea 37,312,608 

Cocoa 6,000,000 

Total $1,228,674,925 

The  consumption  of  spirits  per  capita  fell  from  5.4 
liters  in  1891  to  4.8  liters  in  1900;  wine,  from  1.7  to  1.5 
liters;  and  beer  increased  from  57.9  to  60.6  liters.  This 
indicates  that,  in  general,  the  use  of  alcoholic  beverages 
is  not  on  the  increase. 

Condiments. — Condiments  are  substances  added  to  food 
to  increase  its  palatability  and  to  stimulate  the  appetite. 
The  principal  condiments  are  vinegar  and  lime-  and 
lemon-juice  when  acids  are  desired,  and  mustard  and 
pepper.  These  substances  play  an  important  part  in 
digestion  and  nutrition.  Their  principal  hygienic  inter- 
est is  with  regard  to  excessive  usage.  The  excessive  use 
of  vinegar  tends  to  produce  a  watery  condition  of  the 
blood,  and  is  therefore  injurious.  The  excessive  use  of 
mustard  and  pepper  produces  overstimulation  of  the 
digestive  function,  and  finally  leads  to  irritation  and  in- 
flammation of  the  mucous  membrane  of  the  gastro- 
intestinal tract. 

Adulterations  of  Food. — Adulterations  of  food  are  of 


ADUL  TERA  TIONS  OF  FOOD.  229 

two  kinds,  injurious  and  non-injurious  to  health.  Those 
which  are  without  injurious  effect  are  the  most  numerous, 
yet  they  are  of  importance  because  of  their  fraudulent 
character.  They  are  chiefly  of  two  kiuds,  the  substitu- 
tion of  an  inferior  grade  and  the  substitution  of  inert 
foreign  substances.  They  are  of  hygienic  importance 
because  the  food  so  adulterated  is  of  lower  nutritive  value, 
and  may,  therefore,  lead  to  deficient  nutrition.  In  this 
manner  they  may  pave  the  way  to  disease  by  reducing 
the  natural  resistance  of  *the  body.  A  large  majority  of 
this  class  of  adulterants  is  used  to  increase  bulk  and 
weight,  cheapen  the  article,  and  rob  the  consumer. 
Among  the  poisonous  adulterants  employed  are  those 
used  to  color  and  cheapen  confectionery,  liquors,  and 
canned  vegetables,  and  the  various  antiseptics  employed 
to  preserve  food. 

Milk  is  most  frequently  adulterated  by  the  addition  of 
water,  and  at  times  by  the  abstraction  of  some  of  the 
cream.  Milk  altered  in  this  way  is  not  directly  injurious 
to  health,  as  a  rule,  but  may  be  indirectly  injurious  be- 
cause of  its  altered  nutritive  character.  This  form  of 
adulteration  may  also  be  directly  injurious  to  health 
when  the  milk  is  diluted  with  polluted  water.  Milk  is 
also  adulterated  by  the  addition  of  coloring-matter  to 
conceal  dilution  with  water  and  the  abstraction  of  cream, 
as  well  as  by  the  addition  of  various  preservatives.  The 
latter  are  all  directly  injurious  to  health  when  used  for  a 
considerable  time. 

Butter  is  usually  adulterated  by  the  addition  of  other 
animal  and  vegetable  fats,  or  the  entire  substitution  of 
these  fats  for  the  butter  fats.  While  these  fats  are  some- 
what more  difficult  of  digestion,  they  are  perhaps  not 
otherwise  injurious  to  health.  The  custom  of  adding 
chemical  preservatives  to  the  milk  supplied  to  creameries, 
as  now  practised  by  small  farmers  who  store  the  milk  for 
several  days  before  delivering  it,  yields  butter  containing 
these  preservatives.  Such  butter,  when  used  constantly 
in  large  quantities,  may  prove  injurious  to  health. 


230  FOOD  AND  DIETING. 

Tea  is  adulterated  in  different  ways.  It  may  be  treated 
with  different  substances  to  impart  a  definite  color  to  the 
leaves;  it  may  be  partly  exhausted  of  its  active  principle 
and  extractives  ;  there  may  be  a  substitution  of  foreign 
leaves,  such  as  those  of  the  ash,  willow,  sloe,  birch, 
hawthorn,  raspberry,  etc. ;  the  addition  of  foreign  astrin- 
gents, as  catechu  ;  or  the  addition  of  different  forms  of 
mineral  matter,  as  soapstone,  gypsum,  iron  salts,  copper, 
sand,  etc. 

Coffee  is  adulterated  by  the  addition  of  coloring-matter, 
the  addition  and  substitution  of  chicory,  acorns,  figs, 
leguminous  seeds,  and  cereals.  While  these  substitutes, 
or  imitation  coffees,  are  without  detriment  to  health,  they 
are  distinct  frauds,  and  are  indirectly  injurious  when  the 
stimulating  influence  of  coffee  is  especially  desired. 

Cocoa  is  very  commonly  adulterated,  and  sugar  and 
starch  are  most  frequently  employed  for  this  purpose. 
The  addition  of  these  adulterants  necessitates  the  addi- 
tion of  some  coloring-matter  to  conceal  their  presence. 

Lard  is  commonly  adulterated  by  the  addition  and 
substitution  of  cottonseed  oil;  stearins  derived  from  lard, 
beef  fat,  and  cottonseed  oil;  and  the  fat  of  animals  that 
have  died  of  disease. 

Canned  vegetables  are  adulterated  by  the  addition  of 
salts  of  copper  and  zinc  to  give  them  a  bright-green  color. 
These  salts  are  often  present  in  sufficient  quantities  to  be 
directly  poisonous.  Canned  vegetables  are  also  frequently 
adulterated  by  the  addition  of  antiseptic  substances  to 
assist  in  preserving  them.  These  substances  are  all  more 
or  less  poisonous,  especially  when  used  for  some  time. 
Canned  vegetables  also  frequently  contain  lead  from  the 
vessels  containing  them.  In  Germany  the  law  requires 
that  the  tins  employed  to  hold  the  canned  good  shall  not 
contain  more  than  i  per  cent,  of  lead.  In  this  country 
there  is  no  restriction,  and  as  high  as  12  per  cent,  of  lead 
has  been  found. 

Malt  liquors  are  most  frequently  adulterated  by  the 
addition  of  preservatives,  especially  salicylic  acid.     The 


AD UL  TERA  TIONS  OF  FOOD.  23 1 

presence  of  salicylic  acid  in  beer,  for  instance,  cannot 
fail,  in  time,  to  give  rise  to  disturbances  of  the  health  in 
those  who  take  large  quantities  of  it  daily. 

Mustard  and  pepper  are  frequently  adulterated  by  the 
addition  of  flour,  rice,  corn,  and  ginger. 

Vinegar  is  adulterated  by  the  addition  of  the  mineral 
acids  and  water. 

In  1898  the  General  Assembly  of  Kentucky  enacted  a 
law  providing  for  the  inspection  of  food-products  sold  in 
that  State.  During  1898  and  1899,  727  samples  of  food- 
products  were  collected,  of  which  290  were  found  to  be 
adulterated.  The  inspectors  state  that  "fully  40  per 
cent,  of  all  samples  of  food  taken  have  been  found  adul- 
terated. Some  of  the  adulterants  used  are  injurious  to 
health;  others  have  been  put  in  to  cheapen  articles  of 
food."  As  examples  of  the  former,  the  inspectors  found 
so-called  "fruit  jellies"  made  wholly  or  in  part  of  glue 
and  artificial  coloring-  and  flavoring-matters.  They 
found  salicylic  acid,  sometimes  in  large  quantities,  in 
tomato  catsups,  preserves,  and  other  food-products  which 
were  sold  as  pure,  and  formaldehyd  and  other  preserva- 
tives in  milk.  The  most  striking  example  of  this  form 
of  adulteration  was  found  in  essence  of  peppermint  and 
essence  of  cinnamon.  These  extracts  both  contained 
wood  alcohol  as  one  of  the  ingredients.  These  analyses 
indicate  the  great  necessity  of  the  systematic  control  of 
all  food-products,  in  order  to  prevent  fraud  and  injury 
from  adulterations. 

A  committee  of  the  United  States  Senate  has  investigated 
the  extent  of  food  adulterations  in  this  country,  and  the 
disclosures  made  by  eminent  chemists  show  adulteration 
of  a  large  number  of  food-products.  Samples  of  coffee  ber- 
ries were  submitted  to  the  committee  (which  could  not  be 
distinguished  from  the  genuine  by  casual  examination), 
that  were  composed  of  clay ;  spices  that  were  prepared  from 
prune-stones  and  cocoanut-shells ;  mustard  consisting  prin- 
cipally of  plaster-of- Paris;  pepper  which  was  90  per  cent, 
charcoal  and  sawdust;  wheat  flour  which  contained  only 


232  FOOD  AND  DIETING. 

a  small  percentage  of  residue  of  wheat ;  jellies  made  of 
glucose  and  starch  colored  and  flavored  artificially,  and 
preserved  with  salicylic  acid;  and  olive  oil  which  con- 
tained less  than  lo  per  cent,  extract  of  olives,  the  prin- 
cipal ingredient  being  cottonseed  oil.  All  of  these  sam- 
ples had  been  purchased  in  the  market.  Other  adultera- 
tions which  these  chemists  frequently  found  were:  Sali- 
cylic acid  in  beer;  temperance  drinks,  such  as  raspberry 
soda,  containing  sufficient  anilin  dye  in  a  glassful  to  color 
a  piece  of  flannel  12.5  centimeters  (5  inches)  square;  and 
the  extensive  use  of  borax  as  a  preservative  for  meat, 
poultry,  and  fish.  While  only  a  few  of  these  adulter- 
ants are  directly  prejudicial  to  health,  they  are,  however, 
gross  frauds,  and  should  be  prohibited. 

Dietaries. — The  diet  of  different  individuals  is  in- 
fluenced by  a  great  many  conditions,  such  as  the  finan- 
cial and  social  status,  the  age,  sex,  and  state  of 
health,  the  temperature  and  climate  of  the  place,  the 
amount  of  work  performed,  and  the  availability  of  dif- 
ferent articles  of  food.  Diet  is  also  influenced  to  a  great 
extent  by  the  habits  and  idiosyncrasies  of  the  individual. 
Moleschott's  standard  diet  is  generally  considered  to  be 
a  fair  average  diet  for  an  adult  man.  According  to 
De  Chaumont,  a  certain  definite  proportion  between  the 
carbon  and  nitrogen  ought  to  be  maintained.  This 
proportion  should  be  nitrogen  i  to  carbon  15. 

Diet  in  Infancy — The  natural  diet  of  infants  for  the 
first  fifteen  to  eighteen  months  is  the  mother's  milk.  If 
this  fails,  it  is  necessary  to  substitute  some  artificial  food. 
A  good  substitute  for  mother's  milk  is  cows'  milk. 
Since  cows'  milk  is  richer  in  proteid  material  and  poorer 
in  sugar  than  mother's  milk,  it  is  necessary  to  dilute  the 
milk  and  at  the  same  time  sweeten  it.  The  extent  of 
the  dilution  of  cows'  milk  required  must  be  determined 
with  regard  to  the  purity  and  richness  of  the  cows'  milk, 
and,  especially,  with  reference  to  the  digestive  powers  of 
the  infant.     The  milk  of  the  goat,  ass,  and  mare  are  also 


DIETARIES.  233 

good  substitutes  for  mother's  milk.  In  some  localities 
these  are  more  easily  obtained  than  cows'  milk.  All 
farinaceous  foods  should  be  avoided  until  the  incisor 
teeth  have  made  their  appearance. 

Diet  in  Childhood. — After  the  period  of  infancy  the 
diet  may  be  gradually  varied  by  the  addition  of  rice  or 
arrowroot  to  the  milk,  and  by  supplying  one  soft-boiled 
^^•g  daily,  Konig  gives  the  following  as  a  complete  daily 
diet  for  children  of  six  to  seven  years  of  age :  Meat 
(raw),  170  grams;  bread,  300  grams;  potatoes,  180  grams; 
fat  (butter  and  lard),  15  grams;  milk,  250  grams;  flour, 
for  soup,  100  grams;  vegetables  fvarious),  180  grams;  or 
a  total  of  1 195  grams.  This  yields  78  grams  of  nitrogen, 
43.3  grams  of  fat,  and  281  grams  of  carbohydrates. 

Subsistence  Diet  for  Adults. — Playfair  gives  the  diet 
sufficient  for  the  internal  mechanical  work  of  the  body  as 
follows:  Proteids,  57  grams;  fat,  14  grams;  carbohydrates, 
340  grams;  and  salts,  14  grams;  but  it  is  doubtful  if  an 
average  man  could  subsist  on  this  diet  without  losing 
weight,  as  there  is  no  allowance  for  any  bodily  exertion. 
When  allowance  is  made  for  slight  bodily  exertion  the 
amounts  are  as  follows:  Proteids,  71  grams;  fats,  28 
grams;  carbohydrates,  340  grams;  and  salts,  14  grams. 
For  moderate  work  (93  kilogram-meters),  Moleschott 
gives  the  following  amounts  for  a  man  of  68  kilograms: 
Proteids,  130  grams;  fats,  84  grams;  carbohydrates,  404 
grams;  and  salts,  30  grams.  For  a  man  performing  very 
laborious  work,  or  for  a  soldier  in  the  field,  the  amounts 
should  be:  Proteids,  170  to  198  grams;  fats,  99  to  128; 
carbohydrates,  454  to  510  grams;  and  salts,  34  to  43 
grams. 

A  balanced  ration  is  a  diet  in  which  the  ingesta  are  just 
equal  to  the  excreta.  As  an  instance  of  complete  equi- 
librium in  a  man  weighing  70  kilograms,  embracing  both 
the  nitrogen  and  carbon  of  the  ingesta  and  excreta,  the 
following  balance  table  may  be  given  (Burdon-Sander- 
son): 


234 


FOOD  AND  DIETING. 


Incomings. 

Outgoings. 

Food. 

N. 

c. 

Excreta. 

N. 

c. 

loo  gm.  proteids  .    .    . 
lOO  gm.  fat  .         ... 

15-5 

53- 
79- 
93- 

Urine 

Feces    

Respiration 

14.4 
l.I 

6.16 

10.84 

208  00 

250  gm.  carbohydrates 

15-5 

225. 

15-5 

225. 

The  following  is  an  instance  of  a  balance  table  (Neu- 
meister)  of  a  man  weighing  70  kilograms,  showing 
nitrogenous  equilibrium  only,  some  of  the  carbon  of  the 
ingesta  (mostly  representing  stored  fat)  not  reappearing 
in  the  excreta: 


Incomings. 

Outgoings 

Food. 

N. 
19-5 

c. 

Excreta. 

N. 

c. 

137  gm.  proteids  .    .    . 
117  gm.  fat 

[315-5 

Urine 

Feces    

Respiration 

17.4 

2.1 

12.6 

14-5 

352  gm.  carbohydrates 

248.6 

195 

315-5 

19-5 

275-7 

It  has  been  found  that,  although  work  can  be  done  on 
a  non-nitrogenous  diet,  it  does  not  follow  that  nitrogen 
is  unnecessary.  Experience  has  shown  that  nitrogen 
must  be  supplied  when  work  is  done,  and  that  the 
amount  must  increase  with  the  amount  of  work  done. 
When  no  nitrogen  is  ingested  the  body  uses  some  of  its 
own  nitrogen,  and  becomes  fatigued  after  a  small  amount 
of  work  is  performed. 

Diet  for  Old  Age — Konig  gives  the  minimum  diet  for 
an  old  man  as  follows:  Proteids,  100  grams;  fats,  68 
grams;  and  carbohydrates,  350  grams.  For  an  old 
woman  he  gives  the  following  amounts:  Proteids,  80 
grams;  fats,  50  grams;  and  carbohydrates,  260  grams. 
The  food  of  the  aged  should  be  easily  digested.  With 
decreased  physical  energy  the  digestive  powers  are  also 
lowered,  and  hence  the  nature  of  the  food  has  to  be 
regulated.  Over-indulgence  is  especially  to  be  avoided 
in  the  aged.  Milk,  grains,  and  fruit  are  well  adapted 
for  aged  persons. 


DIETARIES.  235 

In  an  article  on  "Vegetarianism,"  A.  Schoenstadt^ 
states  that:  "  There  are  two  parties  among  vegetarians — 
the  one  excludes  all  animal  nutritive  materials  of  what- 
ever nature,  and  the  radical  adherents  live  on  only  a  few 
vegetables,  namely,  cereals,  fruit,  baked  food,  and  water. 
The  other  party  uses,  besides  vegetable  food,  also  animal 
food  materials  which  are  obtained  without  killinsf  the 
animals,  as  eggs,  milk,  cheese,  butter,  honey.  This  is 
really  not  vegetarianism,  but  a  mixed  diet." 

Schoenstadt  believes  that  it  is  possible  to  subsist  on  a 
purely  vegetable  diet,  but  states  that  it  is  not  sufficient 
nor  natural  for  man.  He  is  of  opinion  that  there  is  great 
danger  connected  with  a  vegetable  diet: 

a.  Because  the  nutritive  materials  supplied  are  in- 
sufficient to  meet  the  requirements  of  the  organism. 

b.  Because  this  diet  leads  to  grave  digestive  dis- 
turbances. 

He  regards  this  diet  as  insufficient  for  the  inmates  of 
institutions  and  prisons. 

Influence  of  Insufficient  Food — Deficiency  in  proteid 
materials  in  the  dietary  is  attended  with  lessened  activity 
and  a  general  lowering  of  the  vitality  of  the  body.  This 
adynamic  condition  favors  the  contraction  of  specific  dis- 
eases. The  omission  of  fats  from  the  dietary  results  in 
illness  in  a  few  days.  The  body  is  unable  to  make  up  its 
carbon  deficit  from  the  other  food-substances.  Starch 
can  be  omitted  from  the  dietary  for  a  long  time  without 
detriment  if  fat  is  given.  Deficiency  •  in  salts  in  the 
dietary  is  attended  by  malnutrition  and  a  disorganized 
condition  of  the  blood. 

A  form  of  deficient  nutrition  which  was  formerly  quite 
common,  and  is  still  seen  at  times,  is  known  as  scurvy. 
This  condition  is  brought  about  by  a  deficiency  of  fresh 
vegetables  and  fresh  fruits,  and  sometimes  to  deficiency 
in  fresh  meats.  It  appears  to  be  due  to  the  absence  from 
the  dietary  of  certain  organic  acids  and  their  salts. 

Influence  of  Excessive  Amounts  of  Food. — When  much 

^  Deiitsch.  Vierteljahr.  f.  oeffentJ.  Gesiindheitspflege,  Bk.  xxxii.,  S.  597. 


236  FOOD  AND  DIETING. 

larger  amounts  of  food  are  taken  than  can  be  utilized 

by  the  body  the  effects  are  manifested  in  dyspepsia, 
diarrhea,  and  gastro-intestinal  irritation.  Gout  is  a  con- 
dition of  the  system  in  which  the  function  of  the  liver 
and  kidneys  is  disturbed  because  of  long-continued  efforts 
at  eliminating  excessive  amounts  of  proteid  materials 
ingested  into  the  system.  Excessive  amounts  of  proteid 
material  with  deficient  fat  lead  to  wasting  of  the  body- 
fat.  Excessive  amounts  of  fat  and  starch  in  the  food 
lead  to  corpulency  and  disordered  function  of  the  diges- 
tive organs. 

"Nutritional  Diseases. — Several  diseases  are  now  dem- 
onstrated to  be  due  to  faulty  nutrition,  though  formerly 
one  of  these  diseases  was  regarded  as  highly  infectious — 
namely,  beriberi.  Even  to-day  the  quarantine  regulations 
adopted  by  the  Pennsylvania  Quarantine  Board  for  the 
port  of  Philadelphia  include  beriberi  among  the  quaran- 
tinable  diseases. 

Scurvy. — For  a  long  time  scurvy  was  a  scourge  on  land 
and  sea,  but  since  the  demonstration  by  Captain  Cook  in  his 
voyage  around  the  world  that  this  disease  could  be  pre- 
vented by  including  lemons  in  the  dietary  of  sailors,  we 
have  learned  that  the  disease  can  be  prevented  by  limiting 
the  quantity  of  salted  meats  in  the  dietary  and  adding 
fresh  vegetables  and  fruits,  or  even  citric  acid  and  vinegar. 
Scurvy  is  to-day  a  rare  disease  among  civilized  people. 

Beriberi. — The  disease  develops  because  of  the  absence 
from  the  diet  of  some  substance  or  substances  necessary 
for  the  normal  nutritive  processes  of  the  body,  most  com- 
monly a  diet  consisting  largely  of  polished  rice.  Strong 
and  Crowell  ^  have  shown  that  the  disease  may  occur  in 
man  under  the  most  favorable  hygienic  conditions,  with 
exception  in  regard  to  diet.  Beriberi  in  man  may  be 
caused  by  limited  diets  which  do  not  include  polished  rice, 
according  to  the  observations  of  Alex  Hoist  ^  on  the  occur- 

1  The  Philippine  Journal  oj  Science,  Sspt.  13,  191 2,  p.  271. 

2  Jour  oj  Hygiene,  1907,  p.  619. 


NUTRITIONAL  DISEASES.  237 

rence  of  the  disease  on  Norwegian  ships ;  of  Little  ^  on  the 

existence  of  beriberi  on  the  coasts  of  Labrador  and  New- 
foundland, where  white  wheat  flour  is  the  chief  article 
of  diet  in  certain  seasons;  and  of  Lovelace  ^  as  to  the 
occurrence  of  cases  in  Brazil. 

The  observations  of  Fletcher^  and  Fraser  and  Stanton* 
have  shown  that  diets  consisting  chiefly  of  polished  rice 
are  the  common  cause  of  beriberi  in  the  Orient.  The 
substitution  of  unpolished  rice  for  polished  rice  eliminates 
beriberi.  Gibson^  found  that  the  addition  of  calcium 
lactate  to  a  polished-rice  diet  served  to  delay  the  onset  of 
polyneuritis  in  fowls.  Vedder  and  Clark  ^  found  that  the 
addition  of  peas  and  peanuts  to  a  polished- rice  diet  pre- 
vented the  development  of  polyneuritis  in  fowls. 

Beriberi  was  demonstrated  by  Baron  Takaki  to  be  due 
to  the  use  of  diet  consisting  largel)-  of  rice,  and  that  it 
could  be  prevented  by  the  addition  of  small  quantities 
of  meat  and  legumes  to  the  dietary.  It  seems  evident 
from  the  experimental  study  of  the  question  that  beriberi 
is  caused  by  a  diet  deficient  in  some  as  yet  unknown  sub- 
stance (vitamine)  which  is  contained  in  the  polishings 
removed  in  the  process  of  polishing,  and  that  unpolished 
rice  does  not  cause  beriberi. 

The  nature  of  the  substance  removed  from  rice  in  the 
process  of  polishing  has  not  been  determined,  but  it  is  of 
great  physiologic  importance  in  the  nutrition  of  the  body. 
This  substance  is  soluble  in  o.  3  per  cent,  hydrochloric 
acid,  and  is  destroyed  when  heated  to  120°  C.  for  one  hour. 
This  substance  is  also  soluble  in  water  and  in  91  per  cent, 
alcohol. 

Pellagra. — Lombroso  and  his  followers  have  contended 
for  many  years  that  pellagra  is  due  to  an  intoxication 
produced  by  poisons  developed  in  spoiled  corn  through 

^  Jour.  Am.  Med.  Assoc,  191 2,  p.  2029. 

2  Ibid.,  p.  2134., 

^Lancet,  1907,  p.  I77S- 

«Ibid.,  1909,  p.  451. 

'^Philippine  Jour,  of  Science,  Sect.  B,  1913,  p.  351. 

^Ibid.,  191 2,  p.  423. 


238  FOOD  AND  DIETING. 

the  action  of  certain  micro-organisms  which  in  themselves 
are  harmless  to  man.  Sambon  ^  believes  that  the  disease 
is  due  to  a  protozoal  organism  in  all  probability  distributed 
b}^  a  species  of  Simulium,  the  sand  fly  in  Europe.  Niles  ^ 
believes  that  the  evidence  in  support  of  Sambon' s  belief 
is  insufficient,  and  that  the  intoxication  theory  of 
Lambroso  gives  the  most  satisfactory  explanation  of  the 
cause  and  character  of  the  disease. 

^  Policlinico,  Rome,  1910,  abstract  Jour.  Am.  Med.  Assoc,  55,  1910,  361. 
^Pellagra,  W.  B.  Saunders  Co.,  19 12. 


CHAPTER    VIII. 
EXERCISE. 

In  order  to  maintain  a  perfect  state  of  health  of  the 
body  it  is  essential  that  each  organ  has  a  certain  amount 
of  exercise.  All  the  bodily  functions  are  attended  with 
rhythmic  motion,  and  these  movements  are  facilitated  by 
exercise.  If  there  is  deficient  exercise  of  a  portion  of 
the  body,  continued  for  some  time,  the  nutrition  of  this 
portion  is  impaired,  the  organs  or  members  involved 
decrease  in  size  and  eventually  degenerate  in  structure  as 
well  as  in  function.  Overexertion  of  a  portion  of  the 
body  leads  to  abnormal  nutrition  and  development  of  the 
organs  or  members  involved,  and  if  continued  for  some 
time  degeneration  may  occur,  which  is  as  great  as  that 
resulting  from  disuse  of  the  organs.  It  is  essential, 
therefore,  that  the  exercise  is  as  uniform  as  possible  for 
all  the  organs  and  members  of  the  body  so  as  to  avoid 
over-  or  under-stimulation  of  any  of  its  parts.  Perfect 
health  is  dependent  upon  the  uniform  stimulation  of  all 
the  functions,  so  that  all  the  organs  may  be  in  a  condition 
to  act  in  their  natural  way  and  normal  capacity. 

The  amount  of  energy  expended  in  walking  on  a  level 
is  usually  assumed  to  equal  that  required  to  lift  one- 
twentieth  of  the  body-weight  through  the  distance 
walked.  The  most  important  effect  of  muscular  exercise 
of  any  kind  is  produced  on  the  lungs  and  circulation. 

Effect  on  the  lyungs. — Smith  has  found  the  effect  of 
exercise  on  the  amount  of  air  respired,  to  vary  in  direct 
proportion  with  the  amount  of  exertion.  Taking  the 
recumbent  position  as  unity,  he  found  the  amounts  of 
air  inspired  as  follows: 

239 


240 


EXERCISE. 


Recumbent  position 1 .00 

Sitting       1. 18 

Standing 1. 33 

Singing 1. 26 

Walking  I  mile  per  hour  ....  1. 90 
Walking  2  miles  per  hour  .  .  .2.76 
Walking  3  miles  per  hour  .  .  .  3.23 
Walking  and  carrying  15  kg.    .    .  3.50 


Walking  and  carrying  28.5  kg.  .  3.84 
Walking  and  carrying  53.5  kg.  .  4.75 
Walking  4  miles  per  hour  .  .  .  5.00 
Walking  6  miles  per  hour     .    .    .  7.00 

Riding  and  trotting 4.05 

Swimming 4-33 

Treadmill 5.50 


Under  ordinary  circumstances  a  man  inspires  8.5  liters 
of  air  per  minute;  if  he  walks  6|-  kilometers,  or  4  miles, 
per  hour  he  inspires  (8.5X4=)  34  liters;  if  he  walks 
9^  kilometers,  or  6  miles  per  hour  he  inspires  (8.5  X  6  =) 
51  liters.  With  increased  amount  of  work  there  is  an 
increased  amount  of  carbon  dioxid  exhaled.  The  rela- 
tive amount  of  carbon  dioxid  exhaled  is  greater,  the 
larger  the  amount  of  work  performed,  on  account  of  the 
increased  oxidation  because  of  the  muscular  exertion. 
Pettenkofer  and  Voit  found  the  relative  amounts  of 
oxygen  absorbed,  and  of  carbon  dioxid,  water,  and  urea 
eliminated  in  rest  and  while  at  work  to  be  as  follows: 


Weight  of  man  experimented  upon  = 
60  kilograms. 

Absorption 
of  oxygen 
in  grams. 

Elimination  in  grams  of— 

Carbon 
dioxid. 

Water. 

Urea. 

Rest 

Work 

708.9 

954-5 

9II-5 

1284.2 

828.0 
2042.1 

37-2 
37.0 

Excess  and  deficiency  during  work    . 

245.6 

372.7 

I2I4.1 

0.2 

The  increased  amount  of  carbon  dioxid  eliminated 
during  exercise  indicates  the  necessity  of  an  increased 
amount  of  carbon  in  the  food  of  persons  performing 
work  requiring  much  muscular  effort.  This  increased 
amount  of  carbon  is  best  given  in  the  form  of  fats, 
rather  than  in  the  form  of  starches.  The  increased 
elimination  of  water  calls  for  an  increased  supply  of 
water  with  the  food,  and  especially  as  drink.  It  is 
preferable  to  take  this  in  the  form  of  plain  water. 
Alcoholic  beverages  decrease  the  elimination  of  carbon 
dioxid  by  the  lungs,   and  are  therefore  contraindicated 


EFFECT  ON   THE   CIRCULATION.  241 

during  muscular  exercise.  For  this  reason  all  alcoholic 
beverages  are  prohibited  for  athletes  while  in  training. 

Effect  on  the  Circulation. — The  first  effect  of  exercise 
is  to  increase  the  rapidity  and  force  of  the  heart  action, 
causing  increased  blood-supply  to  the  muscles,  as  well  as 
to  all  the  organs.  Excessive  exercise,  when  continued  for 
some  time,  leads  to  irregular  action  of  the  heart,  accom- 
panied by  great  rapidity  and  disturbance  of  its  rhythmic 
action.  Such  a  condition  is  highly  injurious,  and  calls 
for  prompt  cessation  of  the  exercise. 

Long-continued  strenuous  labor,  or  excessive  exercise, 
leads  to  hypertrophy  of  the  heart-muscle  and  increased 
caliber  of  the  heart  cavities.  Such  a  condition,  when 
once  established,  remains  permanent.  This  condition  is 
quite  common  in  laborers  who  have  performed  unusually 
hard  work  for  some  years,  in  soldiers  who  have  been 
obliged  to  take  very  long  and  forced  marches,  and  in 
athletes  who  have  been  in  hard  training  for  some  time. 

On  the  other  hand,  deficient  exercise  leads  to  degenera- 
tion of  the  heart-muscle,  weakening  of  the  heart  action 
and  of  the  general  circulation.  In  this  condition  there 
may  be  dilatation  of  the  heart  cavities  without  compen- 
satory hypertrophy  ;  unusual  deposition  of  fat  on  the  out- 
side of  the  heart,  and  even  between  the  muscular  bundles  ; 
and  fatty  degeneration  of  the  heart-muscle. 

In  beginning  athletic  training  the  heart  action  should 
be  carefully  noted  in  order  to  determine  whether  it  is 
properly  accommodating  itself  to  the  increased  demands 
made  upon  it  by  the  muscular  exercise,  as  well  as  the 
manner  in  which  it  behaves  during  the  period  of  rest 
after  the  exercise.  After  exercise  the  heart  action  grad- 
ually slows  down  and  falls  slightly  below  the  normal. 
The  extent  to  which  the  heart  action  falls  below  the 
normal  indicates  the  amount  of  fatigue  produced,  as  well 
as  the  compensating  power  of  the  heart. 

With  proper  care,  in  healthy  subjects,  there  is  no  great 
danger  from  athletic  training.  The  amount  of  exercise 
taken  should  be  gradually  increased  as  the  compensating 

16 


242  EXERCISE. 

power  of  the  heart  increases  with  the  demands  made 
upon  it.  The  athletic  training  should  not  be  suddenly 
relinquished.  The  work  should  be  lessened  gradually, 
in  order  to  allow  the  heart  to  accustom  itself  gradually 
to  the  decreased  demands  of  everyday  life.  ' 

Bffect  on  the  Muscles. — The  result  of  repeated  con- 
traction and  relaxation  of  any  group  of  muscles  is  to 
cause  an  increase  in  the  muscular  fibers,  with  increased 
firmness  and  more  active  response  to  the  will-power. 
The  extent  of  growth  is  limited,  however,  and  when  the 
stimulation  is  long  continued,  or  excessive,  degenerative 
processes  set  in.  Under  such  conditions  the  muscles  be- 
come soft  and  flabby,  and  respond  imperfectly  and  feebly 
to  the  will.  During  exercise  there  is  increased  tem- 
perature in  the  muscles,  dependent  to  some  extent  upon 
the  amount  of  work  performed.  There  is  an- increased 
amount  of  carbon  dioxid  formed  in  the  muscles  as  the 
result  of  the  increased  oxidation. 

All  the  muscles  of  the  body  should  be  exercised  as 
uniformly  as  possible.  There  is  less  likelihood  of  mus- 
cular degeneration,  in  certain  groups  of  muscles,  when 
the  entire  muscular  system  is  required  to  do  a  certain 
amount  of  work.  In  training  for  any  particular  kind  of 
athletic  contest,  in  which  certain  groups  of  muscles  are 
specially  called  into  action,  it  is  best  to  vary  the  exercise 
continually  so  as  to  keep  all  the  muscles  fully  developed. 
For  this  purpose  the  training  should  be  so  conducted  as 
to  allow  a  period  of  rest  to  follow  the  special  exercise, 
and  then,  before  resuming  the  training,  a  short  period  of 
exercise  in  the  gymnasium,  or  some  simple  athletic  game, 
is  advisable. 

Fatigue. — As  the  result  of  muscular  exercise  there  is 
a  feeling  of  exhaustion  and  fatigue,  amounting  some- 
times to  actual  pain  in  the  tired  muscles.  This  condition 
is  brought  about  by  the  accumulation  in  the  muscles  of 
the  products  of  their  activity,  especially  paralactic  acid, 
and  to  deficiency  of  oxygen.  During  the  period  of  rest 
the  accumulated  products  are  eliminated  and  the  supply 


EFFECT  ON  THE  ELIMINATION  OF  NITROGEN.    243 

of  oxygen  is  renewed.  There  is  also  a  deficiency  of 
■vrater  in  the  system  as  the  result  of  excessive  elimination, 
and  this  must  be  replaced.  Since  the  bodily  functions 
require  the  presence  of  a  considerable  amount  of  water  in 
the  system,  it  seems  essential  that  during  exercise  the 
loss  of  water  should  be  compensated  by  the  administra- 
tion of  small  amounts  of  water  at  short  intervals.  The 
fatigue  of  the  muscular  system  can  only  be  relieved  by  a 
period  of  rest.  The  heart-muscle,  under  ordinary  work, 
has  a  rest  between  the  contractions,  which  is  about  twice 
as  long  as  the  time  consumed  by  the  contractions,  and 
hence  it  requires  no  additional  rest  to  recover  itself 

:^ffect  on  the  Nervous  System. — The  effect  of  exer- 
cise on  the  nervous  system  is  more  indirect  than  direct  in 
its  nature.  Moderate  exercise  assists  in  maintaining  all 
the  bodily  functions  in  their  normal  condition,  and  hence 
the  nervous  system  is  in  a  position  to  act  most  efficiently. 
This  fact  has  had  abundant  demonstration  in  recent 
years  since  athletic  sports  have  become  such  an  impor- 
tant feature  in  college  life.  It  has  been  found  that,  as  a 
rule,  the  best  athletes  are  rather  above  the  average  in 
their  class  records. 

Overtraining  is  of  course  detrimental  to  the  nervous 
system,  because  it  undermines  the  general  health.  The 
effect  of  active  exercise  upon  the  mental  activity  is 
dependent  to  a  certain  extent  upon  individual  conditions; 
but,  as  a  rule,  it  is  believed  to  be  perfectly  allowable  iii 
students  that  are  able  to  keep  up  with  the  majority  of 
their  class.  It  is  better  to  attain  somewhat  lower  aver- 
ages in  class  standing  than  to  risk  a  breaking  down  of 
the  nervous  system  as  the  result  of  overstudy  or  injury 
of  the  general  health,  because  of  too  close  application  to 
study. 

Effect  on  the  Blimination  of  Nitrogen. — A  large 
number  of  experiments  have  been  made  to  determine  the 
relative  amounts  of  nitrogen  eliminated  during  rest  and 
exercise.  The  results  obtained  indicate  that  during  exer- 
cise the  amount  of  nitrogen  assimilated  is  increased  per- 


244  EXERCISE. 

ceptibly.  The  metabolism  of  nitrogen  is  influenced 
somewhat  by  the  period  of  work  and  rest,  and  the 
severity  of  the  work  performed.  During  a  period  of 
active  exercise  the  amount  of  nitrogen  eliminated  from 
the  kidneys  is  slightly  diminished,  and  after  the  exercise 
there  is  a  slight  excess  of  nitrogen  excreted,  continuing 
for  some  time.  During  severe  exercise  the  amount  of 
nitrogen  eliminated  appears  to  be  increased.  Voit  and 
Krummacher  are  of  the  opinion  that  usually  work  does 
not  directly  produce  a  greater  breaking  down  of  proteid 
matter,  but  that  an  increase  in  the  proteid  cleavage  is 
caused  by  the  increased  combustion  of  the  nitrogen-free 
materials  which  protect  the  proteid  matter.  If  it  were 
possible,  during  the  period  of  work,  to  supply  the  cells 
continuously  with  a  sufficient  amount  of  nitrogen-free 
material,  then  there  would  be  no  increase  in  the  quantity 
of  proteid  material  broken  down.  But  this  is  a  very  dif- 
ficult matter.  Krummacher  believes  that  the  after-effect 
of  muscular  labor  is  not  due  to  the  continued  excretion 
of  nitrogenous  cleavage-products,  but  to  the  fact  that  the 
nitrogen-free  materials  in  the  body  were  used  up,  and 
that  it  takes  some  time  to  provide  the  body  with  a  new 
supply.  In  active  exercise,  therefore,  an  increased 
amount  of  nitrogen  must  be  supplied  in  the  food,  as  well 
as  an  increased  amount  of  carbon.  There  must  also  be 
an  increased  supply  of  salts,  especially  sodium  chlorid 
and  potassium  phosphate,  to  supply  the  loss  in  these 
salts  during  exercise. 

Amount  of  Bxercise  that  Should  be  Taken. — A 
good  day's  work  for  an  average  man  is  considered  to  be 
150,000  kilogram -meters.  Haughton  has  shown  that 
walking  on  a  level  surface  at  the  rate  of  3  miles  (4.8  kilom- 
eters) per  hour  is  about  equal  to  raising  one-twentieth 
of  the  weight  of  the  body  through  the  distance  walked. 

In  order  to  determine  the  work  performed  in  walking 
32,000  meters  per  day,  we  multiply  the  weight  of  the 
body  in  kilograms  by  the  distance  travelled,  the  result 
being   the   kilogram-meters  of  work   performed.      If  a 


AMOUNT  OF  EXERCISE    TO   BE    TAKEN.       245 

pedestrian  walks  32,000  meters  a  day,  without  a  load,  the 
energy  expended,  assuming  him  to  weigh  70  kilograms, 
is  32,000  X  70=  2,240,000  kilogram-meters.  Haughton 
divides  the  work  performed  into  "fatigue  work,"  the 
effort  necessary  to  carry  the  weight  of  the  body,  and 
"useful  work,"  the  energy  expended  in  performing 
labor.  For  instance,  Coulomb  observed  that  the  work 
done  by  porters  employed  to  carry  goods  2000  meters, 
returning  unloaded,  amounted  to  348  kilograms  in  six 
journeys,  or  58  kilograms  at  a  time.  The  useful  work 
performed  was,  therefore,  2000  X  348  =  696,000  kilogram- 
meters;  the  fatigue  work  was  2000  X  2  X  70  X  6  =  1,680,- 
000  kilogram-meters.  This  allows  70  kilograms  as  the 
weight  of  the  porter,  and  takes  into  consideration  that 
the  body  is  carried  in  both  directions,  or  4000  meters. 
The  total  energy  expended  was  2,376,000  kilogram- 
meters.  He  also  found  that  pedlars,  who  always  travelled 
loaded  with  their  packs,  were  able,  with  a  load  of  44 
kilograms,  to  travel  19,000  meters  per  day.  Assuming 
their  weight  of  70  kilograms,  we  find — 

19,000  X  44  =     836,000  kilogram-meters  =  useful  work. 
19,000  X   70  =  1,330,000  kilogram-meters  =  fatigue  work. 
Total  =  2,166,000  kilogram-meters. 

The  energ}^  expended  under  the  foregoing  conditions 
was,  then, 

Man  walking  without  a  load 2,240,000  kilogram-meters. 

Man  alternately  loaded  and  unloaded 2,376,000  " 

Man  loaded  all  day 2,166,000  " 

In  athletic  exercises  it  is  essential  that  the  amount  of 
energy  expended  be  carefully  determined,  in  order  to 
ascertain  whether  the  exercise  is  likely  to  prove  benefi- 
cial or  otherwise.  The  amount  of  energy  expended  in 
athletic  sports  should  not  exceed  that  expended  by  labor- 
ers in  hard  manual  labor.  In  athletic  contests,  of  course, 
the  energy  expended  is  often  in  excess  of  this  amount;  but 
a  period  of  comparative  rest  must  follow  the  contest, 
in  order  to  allow  the  body  to  recuperate  from  the  fatigue 


246  EXERCISE. 

induced  by  the  contest.  The  harmful  effects  of  the 
large  amount  of  energy  expended  in  some  athletic  con- 
tests is  frequently  seen  when  these  contests  take  place  at 
too  short  intervals,  allowing  insufficient  time  for  the  con- 
testants to  recover  from  the  fatigue  of  the  previous  con- 
test. The  same  effects  are  also  noted  in  soldiers  who  are 
compelled  to  make  frequent  forced  marches  over  long 
distances. 

From  what  has  been  learned  of  the  effects  of  exercise, 
it  will  be  seen  that  athletic  training  should  aim  to  in- 
crease the  breathing-power;  to  strengthen  the  power  of 
the  heart's  action;  to  make  the  muscular  action  more 
vigorous  and  enduring;  and  to  decrease  the  amount  of 
fat.  These  results  are  obtained  by  careful  dieting;  by 
regular  and  systematic  exercise;  and  by  increasing  the 
action  of  the  eliminating  organs,  especially  the  skin. 


CHAPTER  IX. 
CLOTHING. 

The  function  of  clothing  is  to  protect  against  the 
weather — heat,  cold,  and  dampness — and  to  protect 
against  injury.  All  other  uses  of  clothing  have  no 
direct  hygienic  interest,  only  indirectly  in  so  far  as  they 
may  be  injurious  to  health. 

Protection  against  Cold. — The  most  important  use 
of  clothing  in  cold  climates  is  to  protect  against  cold. 
Clothing  serves  this  purpose  by  diminishing  the  radiation 
of  heat  from  the  body.  The  radiation  of  heat  from  the 
body  diminishes  with  the  number  of  layers  of  clothing 
worn,  and  is  also  dependent  upon  the  nature  of  the 
clothinof  worn.  If  we  take  the  amount  of  radiation  of 
heat  from  the  naked  body  as  lOO,  the  radiation  is  reduced 
to  73  by  means  of  a  woollen  shirt;  to  60  by  means  of 
both  a  woollen  and  a  linen  shirt;  to  46  by  means  of  a 
woollen  and  a  linen  shirt  and  a  vest;  to  33  by  the  addi- 
tion of  a  coat.  Rubner  found  that  if  the  radiation  at 
15°  C.  is  taken  as  100,  at  23°  C.  it  is  only  69,  at  29°  C. 
it  is  56,  and  at  32°  C.  it  is  31. 

The  radiation  of  heat  is  directly  dependent  upon  the 
thickness  of  the  layer  of  clothing.  If  we  take  the  loss  of 
heat  as  100,  a  thickness  of  i  millimeter  of  cotton  allows  a 
radiation  of  ^']  per  cent. ;  2  millimeters,  of  68  per  cent. ; 
3  millimeters,  of  65  per  cent. ;  4  millimeters,  of  57  per 
cent.;  5  millifneters,  of  53  percent.;  10  millimeters,  of 
41  per  cent. ;  15  millimeters,  of  30  per  cent. 

The  thickness  of  clothing,  in  our  climate,  must  not  be 
so  great  as  to  increase  perceptibly  the  air-pressure  by 
compression,  nor  so  thin  as  to  decrease  perceptibly  the 
air-pressure.     The  thickness  of  the  clothing  is,  therefore, 

247 


248  CLOTHING. 

one  of  the  most  important  features.  The  radiation  of 
heat  from  the  body  is  very  nearly  the  same  whatever  the 
nature  of  the  clothing.  Wool,  silk,  and  cotton  are 
equally  warm  when  thickness  of  the  layer  is  the  same. 
The  most  rational  clothing,  however,  is  that  which  con- 
serves the  heat  of  the  body  with  the  least  quantity  of 
material.  Flannel  would  be  the  lightest  and  warmest; 
but,  since  it  wears  so  rapidly,  woollen  cloth  is  more  ser- 
viceable, because  it  wears  better.  The  smoothly  woven 
cloths  are  not  so  warm  as  the  tricot  cloths,  but  they  are 
more  serviceable. 

The  clothing  should  not  only  be  light,  but  it  should 
functionate  well  with  regard  to  the  absorption  of  moist- 
ure from  the  skin.  It  should  take  up  the  moisture  as 
readily  as  possible,  and  should  quickly  dry  out.  For  this 
reason  the  clothing  worn  next  the  body  should  be  porous, 
so  that  all  the  pores  may  not  be  filled  with  perspiration. 
Closely  woven  goods  is  not  adapted  for  this  purpose. 
Some  authorities  claim  that  linen,  of  coarse  mesh,  is  best 
adapted  for  this  purpose  because  it  does  not  retain  the 
moisture  as  long  as  wool. 

Protection  against  Heat. — The  degree  of  porosity  is 
an  important  feature  in  summer  clothing.  The  color  of 
summer  clothing  is  also  important.  Dark  clothing  ab- 
sorbs heat  to  some  extent,  and  in  consequence  it  is  some- 
what warmer  than  white  fabrics  or  those  of  lighter  colors. 
The  degree  of  porosity  is,  however,  the  most  important 
factor,  because  on  this  property  depends  the  interchange 
of  air  through  the  skin.  The  effect  of  the  direct  radia- 
tion of  heat  from  the  sun  may  be  inhibited  in  part  by  a 
proper  covering  of  the  head.  For  this  purpose  straw  hats 
with  broad  brims  are  most  serviceable.  They  shade  the 
head  and  face,  and  allow  free  ventilation  of  the  scalp, 
with  a  layer  of  air  between  the  head  and  the  covering. 
This  is  important,  because  air  is  a  poor  conductor  of  heat. 

Protection  against  Dampness.  —  During  rainy 
weather  the  use  of  some  impervious  material  serves  to  ex- 
clude the  dampness  from  the  body  and  clothing.     Damp 


PROTECTION  AGAINST  INJURY. 


249 


clothing  is  injurious  not  only  because  it  is  liable  to  pro- 
duce chill,  but  because  it  prevents  the  free  evaporation 
of  heat  and  moisture  from  the  surface  of  the  body.  The 
importance  of  keeping  the  clothing  dry  in  rainy  weather 
is  therefore  self-evident. 

Protection  against  Injury. — Clothing  protects  the 
body  against  mechanical  injury,  from  frost,  or  from  the 
direct  rays  of  the  sun.  Among  civilized  peoples  pro- 
tection of  the  feet  is  also  necessary  to  avoid  injury  or 
annoyance  in  walking  over  rough  ground.  The  sole  of 
the  shoe  should  conform  to  the  shape  of  the  foot.     This 


Fig.  46. — Correct  sole 
(Hueppe). 


Fig.  47. — Shoemaker's 
sole  (Hueppe). 


is  of  the  greatest  importance.  The  length  of  the  sole  is  the 
so-called  Meyer  line  (Fig.  46,  ^Z*),  which  extends  from 
the  middle  of  the  heel  through  the  middle  of  the  great 
toe,  and  lies  parallel  with  the  inner  border  of  the  anterior 
half  of  the  foot.  The  breadth  of  the  sole  is  indicated  by 
the  Starck  line  (Fig.  46,  cd\  which  extends  diagonally 
from  the  head  of  the  first  metatarsal  bone  to  form  the 
letter  V.  The  shoemaker's  sole  is  usually  cut  so  that 
the  shoe  is  symmetrically  divided  right  and  left  by  a  line 
extending  through  the  middle,  and  which  commonly  cor- 
responds to  the  anatomical  axis  (Fig.  47).      As  the  result 


250 


CLOTHING. 


of  wearing   shoes   with  soles   of  this   pattern  we    have 
subluxations  of  the  great  toe  at  ^,  whereby  the  latter  is 


Fig.  48. — Normal  feet  (Whitman). 


Fig.    49. — Proper  soles   for  normal 
feet  (Whitman). 


forced  outward  and  increases  the  prominence  of  the  ball 
of  the  great  toe.     This  dec;reases  the  room  for  the  other 


Fig.   50. — Deformed  feet 
(Whitman). 


Fig.    51. — Shoemakers'  'soles 
(Whitman). 


toes,  and,  in  consequence,  these  are  superimposed  upon 
each  other,  instead  of  lying  side  by  side. 

Figs.    48,  49,   50,   and   51    also   give    the   outlines   of 


INJURIOUS  EFFECTS  OF  CLOTHING.  251 

normal  feet  and  the  manner  in  which  these  normal  out- 
lines are  deformed  by  the  universal  soles  of  the  shoe- 
maker. It  will  be  seen  that  the  shoemakers'  soles,  as 
figured  by  Whitman,  in  no  way  conform  to  the  outlines 
of  normal  feet. 

The  heels  should  be  low,  broad,  and  long,  so  as  to 
afford  proper  support  to  the  body.  High  heels  are  espe- 
cially injurious,  because  they  place  the  larger  part  of  the 
weight  of  the  body  on  the  ball  of  the  foot.  The  shoes 
should  not  be  so  tight  as  to  compress  the  feet.  Laced 
shoes  are  the  most  rational,  because  they  can  be  fastened 
to  the  feet  in  such  a  manner  as  to  allow  the  least  amount 
of  friction.  Rubber  shoes  should  be  worn  only  for  a 
short  time  during  wet  weather,  and  should  be  removed  as 
soon  as  they  are  not  needed. 

Injurious  Effects  of  Clothing.— The  clothing  should 
be  of  such  a  pattern  as  to  conform  to  the  natural  shape 
of  the  body  without  constricting  or  compressing  any  por- 
tion thereof.  With  regard  to  the  covering  of  the  feet, 
this  point  has  already  been  discussed.  Above  all,  there 
should  be  no  constriction  of  the  chest  and  abdomen. 
The  abdominal  organs  and  the  lungs  and  heart  should  be 
as  free  to  act  as  possible.  The  clothing  worn  by  men  is 
quite  rational  with  this  respect,  but  that  worn  by  women, 
in  general,  is  most  irrational.  The  wearing  of  corsets  is 
highly  injurious,  as  has  been  frequently  proved,  and  it  is 
unnecessary  to  adduce  facts  to  prove  the  statement.  Cor- 
sets compress  the  chest  and  abdomen,  thus  impeding 
respiration  and  the  movements  of  the  heart.  The  abdom- 
inal organs  and  muscles  are  also  compressed  and  corres- 
pondingly deformed  and  interfered  with  in  their  normal 
functions.  The  use  of  tight  garters  is  also  injurious. 
The  clothing  of  women,  should  be  suspended  from  the 
shoulders,  and  not  from  the  hips,  in  order  to  diffuse  the 
weight  more  evenly. 

The  wearing  of  heavy  head-coverings  is  also  injurious, 
because  it  places  a  constant  weight  upon  the  spinal  col- 
umn. The  use  of  veils  is  especially  injurious,  because 
of  the  obstructed  vision  which  they  induce.     The  com- 


252  CLOTHING. 

bination  head-covering  worn  by  women  in  mourning  is 
injurious,  and  frequently  leads  to  persistent  nervous  trou- 
ble, as  well  as  to  general  fatigue  from  its  weight.  It  is 
not  unusual  to  see  spinal  curvature  follow  prolonged  wear- 
ing of  the  head-covering  fashionable  in  mourning. 

Reforms  in  dress  are  quite  difficult  to  bring  into  effect, 
especially  if  they  are  opposed  by  ancient  custom  as  well 
as  by  modern  fashion.  As  long  as  a  form  of  dress  is 
fashionable  it  is  difficult  to  induce  any  one  to  relinquish 
it,  no  matter  how  injurious  it  may  be  or  how  desirable 
the  change  from  a  hygienic  point  of  view. 

Cleanliness  in  Relation  to  Clothing. — The  excre- 
tions of  the  body  through  the  skin  are  absorbed  by  the 
clothing,  and  consequently  frequent  changes  should  be 
made  to  prevent  injurious  effects  from  the  accumulation 
of  these  products  in  the  clothing.  The  excretions  of  the 
body  fill  the  pores  of  the  clothing  and  render  it  more  im- 
pervious, and  therefore  less  suited  for  the  interchange 
of  air.  This  is  especially  the  case  in  those  engaged  in 
laborious  work,  where  the  amount  of  perspiration  is 
great. 

Starching  and  ironing  tend  to  close  the  pores  in  cloth- 
ing and  render  it  more  impervious.  The  wearing  of 
unstarched  clothing  in  hot  weather  is,  therefore,  more 
comfortable.  In  winter  starching  and  ironing  serve  to 
conserve  the  heat  of  the  body. 

The  amount  of  clothing  worn  must  be  varied  with  the 
season  of  the  year  and  the  sensations  of  each  individual. 
The  amount  of  clothing  necessary  to  conserve  the  heat 
of  the  body  of  one  person  may  be  entirely  too  light  or 
too  heavy  for  another.  The  changes  from  lighter  to 
heavier  clothing,  and  vice  versa^  should  not  be  made  too 
suddenly.  In  localities  where  there  is  a  variable  climate, 
with  frequent  changes  in  the  temperature  and  humidity 
of  the  atmosphere,  as  is  the  case  in  the  northern  States 
during  spring  and  autumn,  the  change  from  heavy  to 
light  clothing,  and  vice  versa^  must  be  made  with  great 
circumspection,  in  order  to  prevent  the  development  of 
catarrhal  diseases.     The  changes  must  be  made  accord- 


INFECTED   CLOTHES  AND  BEDDING.         253 

ing  to  the  idiosyncrasies  of  the  individual  and  the  season 
of  the  year.  The  change  can  never  be  regulated  by  the 
calendar,  because  the  conditions  vary  perceptibly  from 
year  to  year.  The  time  of  the  year  when  the  changes 
may  be  made  with  safety  must  frequently  become  a 
question  for  the  physician  to  decide  for  those  under  his 
care,  because  of  his  larger  experience  in  questions  of  this 
nature  on  account  of  prolonged  observation  and  study. 
-  Infected  Clothes  and  Bedding. — Viola  and  Morella 
have  recently  published  the  following  conclusions,  based 
upon  their  experiments  : 

Clothing,  linen,  and  other  garments  are  capable  of 
holding  a  relatively  large  number  of  micro-organisms, 
varying  from  915  to  571,962  for  each  square  centimeter 
of  goods.  While  the  greater  part  of  these  bacteria  are 
saprophytic,  pathogenic  germs  are  also  found.  The  num- 
ber of  bacteria  found  in  garments  in  actual  contact  with 
the  human  body  is  in  direct  ratio  to  the  number  of  days 
the  garments  are  worn.  In  general,  the  number  of  bac- 
teria found  in  clothing  of  a  person  is  proportional  to  the 
activity  of  his  occupation.  Wool  has  a  greater  capacity 
for  germs  than  cotton  or  silk.  Corresponding  to  the 
local  bacteriologic  flora  of  the  surface  of  the  human 
body,  there  is  a  quantitative  difference  in  the  bacterial 
contents  of  clothing  covering  different  parts  of  the  skin. 
In  clothing  actually  being  worn,  pathogenic  bacteria 
live  a  shorter  time  than  in  the  same  garments  hanging 
in  a  wardrobe.  Under  all  conditions  pathogenic  bacteria 
contained  in  clothing  gradually  die  out.  There  is,  with 
the  passage  of  time,  a  gradual  diminution  in  the  number 
of  disease-producing  germs  with  which  a  given  article  of 
clothing  has  been  contaminated.  There  is  also  a  pro- 
gressive decline  in  the  power  of  development  of  bacteria, 
as  they  undergo  a  gradual  diminution  in  virulence.  The 
authors  conclude  that  garments  are  a  potent  means  for 
the  diffusion  of  infectious  agents,  and  that  without 
special  treatment  pathogenic  germs  can  retain  their  viru- 
lence in  human  raiment  for  a  considerable  but  not  in- 
definite period. 


,  CHAPTER   X. 
PERSONAL    HYGIENE. 

Perfect  health  is  dependent  upon  the  normal  activity 
of  all  the  organs  of  the  body.  The  organic  functions  of 
the  body  can  be  maintained  in  their  normal  condition 
only  by  observing  all  the  general  hygienic  rules  and 
regulations.  These  principles,  while  they  are  well 
recognized  and  of  the  utmost  general  value,  cannot, 
however,  be  stated  in  very  specific  terms  when  applied 
to  individual  conditions,  because  the  individual  idiosyn- 
crasies of  different  persons  vary  to  such  a  great  extent. 

There  must  be  continuous  moderation  in  diet,  both 
with  regard  to  quality  and  -  quantity.  The  individual 
peculiarities  as  produced  by  inherited  and  acquired 
instincts  influence  the  quality  and  quantity  of  food  that 
are  most  suitable.  The  nature  and  amount  of  work  per- 
formed is  also  an  important  factor  in  the  matter  of  diet. 
So  also  are  the  temperature,  latitude,  and  altitude  of  a 
locality,  and  the  amount  and  nature  of  the  clothing 
worn.  Individual  experience,  therefore,  plays  a  most 
important  part  in  governing  the  diet  of  each  person. 
The  point  to  be  borne  in  mind  is  that  all  excesses  should 
be  avoided.  No  more  should  be  taken  than  the  system 
demands  and  can  conveniently  utilize.  If  this  point  is 
properly  regulated,  one  of  the  principal  factors  in  the  pro- 
duction of  disease  is  eliminated.  The  food  taken  should 
be  slowly  and  thoroughly  masticated.  This  will  favor 
the  admixture  of  a  plentiful  supply  of  saliva,  and  will 
also  facilitate  the  subsequent  steps  in  the  process  of 
digestion.  Proper  mastication  of  the  food  cannot  take 
place  without  sound  teeth.  Defective  teeth  frequently 
lie  at  the  foundation  of  various  affections  of  the  stomach. 

254 


CLEANLINESS.  2  5  5 

The  supply  of  nitrogenous  and  carbonaceous  foods 
should  be  regulated  according  to  the  demands  of  the 
body.  If  there  is  a  deficiency  of  fatty  deposit,  the  supply 
of  carbohydrates  is  probably  insufiBcient;  on  the  other 
hand,  if  there  is  an  excess  of  fatty  deposit,  the  supply 
of  fats  and  carbohydrates  is  excessive.  These  are  points 
that  can  be  regulated  by  each  individual,  to  a  certain 
extent,  though  it  must  be  remembered  that  some  persons 
are  normally  fatter  or  thinner  than  others. 

Cleanliness  is  one  of  the  most  important  factors  in 
the  preservation  of  health.  This  applies  not  only  to 
cleanliness  of  the  body,  but  to  cleanliness  in  every  par- 
ticular of  life.  It  goes  without  saying  that  cleanliness 
of  body,  clothing,  and  habitation  are  essential  to  good 
health.  The  number  of  baths  taken,  and  the  kind  of 
bath,  is  a  matter  that  is  governed  by  individual  condi- 
tions, such  as  habit,  amount  and  character  of  the  work 
performed,  and  the  temperature  of  the  locality. 

Regular  attention  to  the  bowels  is  an  important 
matter  in  regulating  the  health.  The  number  of  move- 
ments a  day  will  be  regulated  by  the  diet  and  habit  of 
each  individual,  though  it  is  generally  conceded  that  one 
movement  a  day  is  desirable  in  order  to  maintain  the 
efficiency  of  the  digestive  apparatus. 

The  regulation  of  the  passions  is  another  matter  for 
individual  control,  though  all  excesses  should  be  avoided. 
The  practice  of  vices  is  to  be  condemned  in  the  most 
forcible  manner  because  of  the  detrimental  influence  upon 
the  nervous  system  and  the  entire  organism.  Parkes 
states  that  "we  know  that  a  widespread  profligacy  has 
eaten  away  the  vigor  of  nations,  and  caused  the  downfall 
of  nations;  but  we  hardly  recognize  that,  in  a  less  degree, 
the  same  causes  are  active  among  us,  and  never  realize 
what  a  State  might  be  if  its  citizens  were  temperate  in 
all  things." 

Cleanliness  of  the  mouth  and  teeth  is  of  the  greatest 
importance.  Proper  care  of  the  teeth,  including  sys- 
tematic  cleansing,  will   go   far   to   preserve  them    in  a 


256  PERSONAL  HYGIENE. 

sound  condition.  This  will  also  serve  to  prevent  the 
accumulation  of  decaying  food  particles  around  the 
teeth  and  gums,  and  thus  prevent  the  decay  of  the  teeth 
and  disease  of  the  gums  and  of  the  mucous  membrane  of 
the  mouth  and  throat.  A  decaying  tooth  should  be  filled 
as  early  as  possible,  in  order  to  preserve  it  and  to  prevent 
more  serious  disease  of  the  maxillary  bone. 

Great  care  should  be  exercised  in  the  selection  of  a 
habitation.  The  nature  of  the  water-supply  is  an  impor- 
tant factor  in  the  preservation  of  health.  If  the  purity 
of  the  water-supply  is  doubtful,  it  will  be  the  wisest 
course  to  have  all.  the  water  boiled.  The  nature  of  the 
soil  is  also  an  important  factor.  Damp  soils,  as  well  as 
recently  made  soils,  should  be  avoided,  because  they  may 
prove  injurious  to  health.  The  material  used  in  con- 
structing the  house  is  of  importance,  as  well  as  the  posi- 
tion of  the  house  with  reference  to  the  points  of  the  com- 
pass. A  southern  exposure  is  usually  preferable  to  a 
northern  exposure.  The  number  and  arrangement  of 
the  windows  should  be  considered.  There  should  be 
plenty  of  light  and  free  access  of  air.  Sunlight  is  the 
great  restorer  and  purifier,  and  it  should  be  freely  ad- 
mitted to  all  houses  when  the  temperature  will  permit. 

The  nature  of  the  occupation  and  its  influence  upon 
health  should  be  carefully  considered.  If  the  occupation 
selected  should  prove  detrimental  to  health,  it  should  be 
discarded  for  one  that  is  less  likely  to  operate  in  the  same 
manner.  If  a  sedentary  occupation  proves  harmful,  it 
should  give  way  to  another  involving  much  outdoor 
activity.  The  amount  of  mental  work  that  may  be  per- 
formed without  injuring  the  health  will  depend  upon  the 
individual  constitution.  A  sedentary  occupation  may  be 
prevented  from  injuring  the  health  by  the  employment 
of  systematic  exercise  of  some  form  or  another.  When- 
ever possible  the  occupation,  as  well  as  the  bodily  exer- 
cise, should  be  of  a  cheerful  nature.  The  exercise  in- 
dulged in  may  often  be  made  most  beneficial  by  taking  it 
in  conjunction  with  other  persons.     For  this  reason  the 


MENTAL  ATTITUDE.  2^7 

dififerent  athletic  sports  are  of  such  great  benefit.  If  out- 
door exercise  be  taken,  it  may  be  made  profitable  as  well 
as  pleasurable  by  combining  it  with  nature  studies. 
Under  such  conditions  the  exercise  is  not  so  likely  to 
become  burdensome,  because  one  loses  sight  of  the  feel- 
ing of  compulsion. 

The  mental  attitude  of  the  individual  is  also  an  impor- 
tant factor  in  preserving  health.  Hopefulness  and  cheer- 
fulness are  great  aids  to  health  because  of  their  beneficial 
influence  on  digestion.  The  mental  condition  is  largely 
under  the  control  of  the  will-power,  and  each  individual 
is  hopeful  and  cheerful  or  morose  and  despondent  as  he 
wills  to  be. 

The  regulation  of  work,  rest,  sleep,  and  meals  is  more 
or  less  under  individual  control.  The  amount  of  sleep 
required  for  perfect  refreshment  varies  with  the  indi- 
vidual. It  is  usually  greater  in  childhood  and  old  age 
than  in  the  prime  of  life.  The  amount  of  sleep  taken  in 
order  to  preserve  the  health  should  be  sufficient  to  prevent, 
if  possible,  a  feeling  of  sleepiness  during  the  day.  It  is 
generally  conceded  that  the  most  refreshing  sleep  is 
obtained  in  the  early  hours  of  the  night,  though  some 
persons  can  accustom  themselves  to  sleep  soundly  during 
any  portion  of  the  twenty-four  hours.  It  is  possible  to 
deprive  one's  self  of  sleep  for  a  considerable  time,  but 
eventually  the  effects  will  be  felt  in  loss  of  nervous 
power.  This  is  especially  the  case  with  those  engaged 
in  mental  work.  Sooner  or  later  a  period  of  insomnia 
supervenes  which  is  not  easily  overcome. 

17 


CHAPTER    XI. 
INDUSTRIAL   HYGIENE. 

iNDUSTRiAiy  hygiene  received  very  little  attention  in 
the  United  States  until  about  1910.  Since  that  time  a 
number  of  important  investigations  have  been  made 
of  the  occupational  hazards  in  various  industries,  and  the 
results  of  these  investigations  have  been  published  in 
the  form  of  bulletins  by  the  Department  of  Labor,  by 
State  Boards  of  Health,  and  in  the  form  of  text-books, 
notably  those  of  G.  Gilman  Thompson,  "Occupational 
Diseases";  George  M.  Price,  "The  Modern  Factory"; 
E.  R.  Hayhurst,  "Industrial  Health-hazards  and  Occu- 
pational Diseases  of  Ohio" ;  George  M.  Kober  and  Wm. 
C.  Hanson,  "Diseases  of  Occupation  and  Vocational 
Hygiene." 

The  rapidity  with  which  this  Hterature  has  been 
pubHshed  is  an  indication  of  the  increasing  impor- 
tance of  the  subject  of  Industrial  Hygiene  as  a 
public  health  problem.  The  European  War  has 
made  the  entire  subject  one  of  the  most  impor- 
tant now  before  the  industrial,  commercial,  and  medical 
world. 

The  influence  of  occupation  upon  the  health  of  laborers 
is  a  subject  of  the  greatest  hygienic  importance.  Certain 
occupations  are  far  more  dangerous  than  others  because 
of  the  liability  to  accident;  some  occupations  are  more 
dangerous  than  others  because  of  poisonous  fumes  and 
gases  that  are  given  off  in  certain  manufacturing  proc- 

258 


INDUSTRIAL  HYGIENE.  259 

esses ;  again,  other  occupations  are  dangerous  to  health 
because  of  various  kinds  of  dusts  that  are  produced,  thus 
leading  to  irritation  of  the  respiratory  organs.  In  other 
occupations  certain  groups  of  muscles  and  certain  organs 
of  the  body  are  used  excessively,  thus  leading  to  defects 
in  these  organs;  while  in  others  a  constrained  attitude  is 
maintained  while  at  work,  or  a  sedentary  life  is  induced, 
which  may  be  the  cause  of  ill  health. 

According  to  Hayhurst  the  most  important  industrial 
health-hazards  are:  Dust,  dirt,  darkness,  dampness, 
devitalizing  air,  heat,  cold,  fatigue,  inactivity,  infection, 
poisons,  compressed  air,  foul  odors,  venereal  diseases, 
and  stimulation.  At  the  present  time  the  most  im- 
portant health-hazards  in  industrial  establishments 
are  various  forms  of  dust,  different  kinds  of  poisons, 
and  accidents.  All  of  the  industrial  health-hazards 
are  preventable  and  many  of  them  can  be  prevented 
through  the  education  of  the  laborers  so  as  to  get 
them  to  realize  the  hazards  encountered  and  the 
measures  to  be  adopted  to  make  their  work  reasonably 
safe. 

The  occupations  which  are  directly  concerned  in  the 
production  of  disease  are  those  in  which  irritating  or 
poisonous  gases  are  produced,  such  as  sulphurous,  nitric, 
and  hydrochloric  acid  fumes;  ammonia,  chlorin,  carbon 
monoxid  and  dioxid,  hydrogen  sulphid  and  carbon  di- 
sulphid,  iodin,  bromin,  and  phosphorus  vapors;  turpen- 
tine and  petroleum  vapors;  mercury,  arsenic,  lead,  zinc, 
and  copper  poisoning;  aniline  vapors;  those  in  which 
irritating  or  poisonous  dusts  are  produced,  such  as  coal- 
dust,  metallic  dust  of  various  kinds,  mineral  dust,  and 
vegetable  dust;  those  in  which  there  is  local  absorption 
of  irritating  or  poisonous  substances,  such  as  arsenic, 
phosphorus,  quinin,  potassium  bichromate,  strong  alka- 
lies, and  petroleum;  those  in  which  there  is  an  elevated 
or  variable  temperature  and  atmospheric  pressure. 

Analyses   of    the   deaths   occurring    in    the   different 


26o 


INDUSTRIAL  HYGIENE. 


occupations  have  given  us  a  knowledge  of  the  relative 
degree  of  danger  from  different  forms  of  industrial  pur- 
suits. Such  an  analysis  has  been  made  of  all  the  deaths 
occurring  in  Massachusetts,  including  all  persons  over 
twenty  years  of  age,  from  May  i,  1843,  to  December  31, 
1885,  by  the  registration  bureau  of  that  State,  The  fol- 
lowing table  gives  the  detailed  results  of  this  analysis. 
The  total  number  of  deaths  was  229,897,  and  the  average 
age  at  death  51.82  years  : 


Occupations. 


Class   I.      Cultivators    of 
the  earth  :  Farmers, 
gardeners,  etc. 
Class     11.        Active     me- 
chanics abroad. 

Brickmakers 

Carpenters  and  joiners 
Calkers  and  gravers     . 

Masons 

Millwrights      ..... 

Riggers 

Ship-carpenters     .    .    . 

Slaters  

Stcine-cutters 

Tanners    ....... 

Class    III.      Active    me- 
chanics in  shops. 

Bakers 

Blacksmiths 

Brewers 

Cabinet-makers      .    .    . 
Calico-printers  .... 

Cord-makers 

Carriage-makers      and 

trimmers. 
Chair-makers     .... 

Clothiers  

Confectioners      .... 

Cook.s 

Coopers 

Coppersmiths     .... 

Curriers 

Cutlers      

Distillers      

Dyers 

Founders 

Furnace-men 

Glassblowers  and  glass- 
makers. 

Gunsmiths 

Hatters 

Leather-dressers   .    .    . 

Machinists 

Millers 

^     Musical  instrument 
makers. 

Nail-makers 

Pail-  and  tub-makers   . 
Painters 


la 


46,182 


17.371 

159 
9,761 

281 
2,889 

188 

237 
1,305 

159 
.1,678 

714 

28,208 


751 

3,615 

63 

1,250 

16 

52 

479 

234 
119 

171 

243 
1,299 

150 
951 
218 
36 
269 
764 
175 
202 

306 
530 
354 
3,761 
386 

61 

279 

7 

3,561 


66.29 


51.34 

49-71 
5S-o6 
58.91 
53-33 
60.43 
55-54 
61.36 
41.69 
41.22 
52.73 
48.80 
49.16 
55-11 
45-14 
50-66 
58.87 
50.42 

51.87 

46.49 
57-25 
45-37 
40.87 
59-88 
46.09 

45-79 
42.01 
58.78 
48.65 
44.82 
46.28 

41.61 

50.3s 
34-55 
46.88 

43-47 
58-69 

49-25 

45.75 
41.86 
45-77 


Occupations. 


Paper-makers 

Piano-forte  makers  .    .    . 

Plumbers      

Potters 

Pump-  and  block-makers 

Reed-makers 

Rope-makers 

Tallow-chandlers  .... 

Tin-smiths 

Trunk-makers 

Upholsterers 

Weavers 

Wheelwrights 

Wood-turners     ..... 
Mechanics    (trade     not") 

specified).  / 

Class  IV.     Inactive   me-  ( 

chanics  in  shops.      J 

Barbers 

Basket-makers 

Book-binders 

Brush-makers 

Carvers 

Cigar-makers      

Clock-  and  watch-makers 

Comb-makers 

Engravers 

Glass-cutters      

Harness-makers    .... 

Jewellers 

Operatives 

Printers 

Sail-makers 

Shoe-cutters 

Shoe-makers 

Silversmiths     or    gold-") 

smiths.  J 

Tailors      

Tobacconists 

Whip-makers 

Wool-sorters 

Class     "V.      No    special") 

trades.  J 

Laborers 

Servants 

Stevedores 

Watchmen 

Workmen     in    powder-"! 

mills.  J 


463 
210 

303 
65 
124 
18 
371 
IIS 
640 
78 
287 
971 
738 
154 

3-369 

28,459 
772 
log 
258 
96 
141 
306 
205 
222 
200 
124 
676 
782 
4,662 
1,243 
310 
795 

14,802 

140 

2,174 
61 

143 
238 

43,716 

42,532 
624 
123 
410 

27 


>  s 


48.6s 
48.30 

36-34 
58.02 
58.23 
45-94 
60.01 

56.75 
42-95 
40.38 
40.98 
44-65 
59-50 

49-54 
47-35 

45-43 

39-34 
60.32 
43-56 
47-36 
37.60 
39-78 
51-47 
54-09 
39-74 
44.40 
50.00 
41.62 
41.28 
40.58 

55-17 
47.06 

46.34 

48.59 

50-19 
50.41 
44-50 
48.92 

49.06 
49.16 
39-15 
54-07 
53-13 

37-41 


INDUSTRIAL  HYGIENE. 


261 


Occupations. 


Class  VI.    Factors,  labor-") 
ing  abroad,  etc.         J 

Baggage-masters   .    .    .    . 

Brakemen 

Butchers 

Chimney-sweepers    .    .    . 

Drivers 

Drovers 

Engineers  and  firemen    . 

Expressmen 

Ferrymen 

Lighthouse-keepers  .    .    . 

Peddlers 

Sextons 

Soldiers 

Stablers 

Teamsters 

Weighers  and  gaugers 

Wharfingers 

Class  VII.     Employed  on) 
the  ocean.  j 

Fishermen 

Mariners 

Naval  officers 

Pilots 

Seamen 

Class  VIII.  Merchants, 
financiers,  agents, 
etc. 

Agents  ....■".. 

Bankers 

Bank  officers 

Boardinghouse-keepers    . 

Booksellers 

Brokers 

Clerks  and  bookkeepers  . 

Druggists   and   apothe-") 
caries.  J 

Gentlemen 

Grocers 

Innkeepers 

Manufacturers 


M    O 

"A 


10,776 

72 

509 


24 
770 

149 

2,926 

654 

2,370 

39 

33 

12,394 

965 

II 

90 

122 

11,206 

27,098 

752 
103 
243 
127 
104 
382 
6,449 
487 

1.993 

1,019 

734 

2,219 


39-36 
36.25 
27.12 
50.50 
34-50 
40.36 
51-32 
41-57 
44.18 

51-27 
60.24 
48.28 
60.01 
28.59 
44.66 
42.31 
57-72 
55.48 

48.57 

44-37 
44- 36 
52.82 
61.63 
48.76 

49.60 

50.62 
59-73 
57-IO 
50.47 
54-75 
52.13 
36-35 
43.86 

68.87 
48.80 
51-63 
5492 


Occupations. 


Merchants 

Newsdealers  or  carriers 

Railroad  agents  or  con- 
ductors. 

Saloon-  and  restaurant- 
keepers. 

Stove-dealers      .... 

Telegraphers 

Traders 

Class    IX.      Professional] 
men.  j 

Actors 

Architects 

Artists 

Civil  engineers 

Clergymen 

Dentists 

Editors  and  reporters  .    . 

Judges  and  justices  .    .    . 

Lawyers 

Musicians 

Photographers 

Physicians 

Professors 

Public  officers     .... 

Sheriffii,  constables, and) 
policemen.  j 

Students 

Surveyors 

Teachers 

Class.  X.     Females  .... 

Domestics 

Dress-makers 

Milliners      

Nurses      

Operatives 

Seamstresses 

Shoe-binders      

Straw-workers 

Tailoresses 

Teachers 

Telegraphers 


6,200 
76 


832 

26 

59 

4,732 


56.4s 
43-78 

41.28 
40.70 

47  46 
29-97 
50.39 


8,306 

52-13 

68 

42.18 

71 

46-23 

306 

45-41 

188 

43-91 

1,560 

60.31 

>93 

45.47 

187 

46.50 

4b 

66.17 

1,017 

56.41 

419 

43-13 

66 

43-79 

1,804 

56.51 

68 

58-44 

637 

56-44 

407 

52.30 

460 

23.67 

125 

54-10 

694 

44.62 

7,387 

39-19 

1,990 

44.11 

595 

42.35 

230 

42.45 

291 

62.62 

2,237 

29.71 

476 

47.25 

8q 

36-78 

123 

35-o8 

353 

51.71 

985 

33.72 

i§ 

27.39 

This  table  is  not  accurate  in  all  its  details,  and  also 
fails  to  present  the  relative  healthfulness  of  different  oc- 
cupations, because  persons  are  constantly  changing  from 
one  occupation  to  another.  It  shows,  however,  very 
clearly  the  relation  of  certain  occupations  to  longevity. 

Dr.  William  Ogle,  who  has  probably  given  more  at- 
tention to  this  subject  than  anyone  else,  in  a  paper  pre- 
sented to  the  Seventh  International  Congress  of  Hygiene, 
1891,  on  mortality  in  relation  to  occupation,  states  that 
"of  all  the  various  influences  that  tend  to  produce  dif- 
ferences of  mortality  in  different  parts  of  a  given  country, 
there  is  none  so  potent  as  the  character  of  the  prevailing 


262  INDUSTRIAL  HYGIENE. 

occupations."  He  states  further  that  "  the  only  method 
of  making  death-rates  that  can  be  safely  compared  with 
each  other  is  the  laborious  plan  of  calculating  the  death- 
rates  for  each  occupation  at  each  successive  age-period, 
and  then  applying  these  successive  death-rates  to  a  popu- 
lation with  precisely  the  same  age-distribution  in  each 
industry.  This  method,  indeed,  is  necessary,  not  only 
when  the  mortality  of  an  occupation  is  being  compared 
with  that  of  any  other,  but  generally  in  all  comparisons 
of  mortality,  as,  for  instance,  in  comparison  between  the 
mortalities  of  different  countries,  or  between  the  mortali- 
ties of  the  two  sexes.  It  is,  however,  a  method  which, 
owing  to  its  laboriousness,  is  rarely  used,  with  the  neces- 
sary consequence  that  many  very  erroneous  comparisons 
are  made." 

He  gives  the  mortality  in  different  industries  and  pro- 
fessions which  were  derived  from  a  comparison  between 
the  census  returns  of  England  for  1881  and  the  death- 
registers  for  the  three  years  1881,  '82,  and  '83.  The 
figures  relate  exclusively  to  males. 

The  lowest  death-rate  obtained  was  that  of  men  in  the 
clerical  profession,  and  for  the  sake  of  comparison  this  is 
taken  as  the  standard,  being  represented  by  100,  and  the 
death-rate  of  each  of  the  other  professions  or  industries  is 
represented  by  a  figure  proportionate  to  this  standard. 

Dr.  Ogle  classes  the  causes  of  high  mortality  under 
seven  general  headings: 

"  I.  Working  in  a  cramped  or  constrained  attitude, 
and  notably  in  such  an  attitude  as  cramps  the  chest  and 
interferes  with  the  action  of  the  heart  and  lungs. 

"2.  Exposure  to  the  action  of  special  poisonous  or 
irritating  substances,  such  as  phosphorus,  mercury,  lead, 
infected  hair  or  wool,  soot,  etc. 

"  3.   Excessive  work,  mental  or  physical. 

"4.  Working  in  confined  spaces  and  in  foul  and  over- 
heated air.  This  is  probably,  in  the  aggregate,  one  of 
the  most  destructive  agencies  in  operation,  because  of  the 
very  large  number  of  trades  that  are  exposed  to  it. 


INDUSTRIAL  HYGIENE. 


263 


Comparative  Mortality  of  Men.,  Tzaenty-five  to  Sixty-Jive 
Years  of  Age.,  in  Different  Occupations .,  1881,  1882, 
and   1883. 


Occupation. 


Comparative 
mortality. 


Clergymen,  priests,  ministers      .    .  loo 

Lawyers 152 

Medical  men 202 

Gardeners 108 

Farmers 114 

Agricultural  laborers 126 

Fishermen I43 

Commercial  clerks  ......  179 

Commercial  travellers 171 

Innkeepers,  liquor  dealers      .    .    .  274 

Inn,  hotel  service 397 

Brewers 245 

Butchers 21 1 

Bakers 172 

Corn-millers 172 

Grocers 139 

Drapers 159 

Shopkeepers  generally 158 

Tailors 189 

Shoe-makers 166 

Hatters 192 

Printers •    .    .  193 

Book-binders 210 


Occupation. 


Comparative 
mortality. 


Builders,  masons,  bricklayers     .    .  174 

Carpenters,  joiners 148 

Cabinet-makers,  upholsterers      .    .173 
Plumbers,  painters,  glaziers    .    .    .  216 

Blacksmiths 175 

Engine-,  machine-,  boiler-makers  .  155 

Silk  manufacture 152 

Wool,  worsted,  manufacture  .    .    .  186 
Cotton  manufacture     .    .    .    .    ,    ,196 

Cutlers,  scissor-makers 229 

Gunsmiths 186 

File-makers 300 

Paper-makers 129 

Glass-workers 214 

Earthenware-makers 314 

Coal-miners 160 

Cornish  miners 331 

Stone,  slate  quarries 202 

Cab,  omnibus  service 267 

Railway,  road,  laborers 185 

Costermongers,    hawkers,     street- 
sellers 338 


"  5.   Excessive  use  of  alcoholic  beverages. 

"6.   Liability  to  fatal  accident. 

"7.   Exposure  to  inhalation  of  dust." 

Under  the  second  cause  Dr.  Ogle  gives  the  following 
table  of  the  comparative  mortality  from  lead-poisoning, 
based  on  the  death-register  for  1879-82,  in  males  over 
fifteen  years  of  age: 

File-makers 466  per  million  living. 

Painters,  plumbers,  glaziers 224 

Earthenware-makers 152 

Gas-fitters 62 

Printers 27 

All  other  males 4 


264 


INDUSTRIAL  HYGIENE. 


Under  the  fourth  cause  he  gives  the  following  table, 
showing  the  effects  upon  the  lungs  alone,  though  the 
lungs  are  not  the  only  organs  affected  by  this  cause. 
Fishermen,  who  suffer  least  from  these  diseases,  are  taken 
as  the  standard,  and  the  mortality  for  this  occupation  is 
represented  as  100. 

Comparative  Mortality  from  Phthisis  and  Lung  Diseases 
of  Men  {Forty-five  to  Sixty-five  Years)  Working  in 
Pure  and  Vitiated  Air. 


Air. 

Occupation. 

Phthisis. 

Diseases  of 

respiratory 

organs. 

Phthisis  and   dis- 
eases of  the  respir- 
atory organs. 

Pure  air 

- 

Fishermen    .... 

Farmers 

Gardeners     .... 
Agricultural  laborers 

55 
52 
61 
62 

45 
50 
56 
79 

100 
102 
117 
141 

Confined  air 

{ 

Grocers 

Drapers    ... 

84 
152 

59 
65 

143 
217 

Highly  vitiatec 
air 

Tailors 

Printers 

144 
233 

94 

84 

238 

Under  the  fifth  cause  he  gives  the  comparative  mor- 
tality from  various  diseases  of  liquor-dealers  and  men 
generally.  The  trade  most  exposed  to  the  effects  of  the 
excessive  use  of  alcohol  is  that  of  dealers  in  these  bev- 
erages— "innkeepers,  publicans,  and  wine-  and  spirit- 
dealers."  The  table  shows  the  comparative  results  ob- 
tained by  taking  the  mortality  of  1000  males  of  cor- 
responding ages. 

Under  the  seventh  cause  he  gives  the  comparative 
mortality  from  phthisis  and  lung  diseases  in  the  various 
dust-inhaling  occupations.  The  effects  of  the  inhalation 
of  dust  are  shown  in  an  increased  mortality  from  phthisis 
and  from  lung  diseases,  though  the  effects  differ  very 
greatly,  not  only  with  the  amount  of  dust,  but  also  with 
the  character  of  the  dust,  the  more  irritating  the  dust 
the  more  injurious  its  effects. 


INDUSTRIAL  HYGIENE. 


265 


Comparative  Mortality  of  Liquor-dealers  attd  Men  gen- 
erally. 


Diseases. 


Men     twenty-five    to    sixty-five 
years  of  age. 


All  males. 


Alcoholism 

Liver  diseases 

Gout 

Diseases  of  the  nervous  system  .    , 

Suicide      

Diseases  of  the  urinary  system  .  . 
Diseases  of  the  circulatory  system 
All  other  causes 

■AH  causes 


10 

39 

3 

119 

14 

41 

120 

654 


1000 


Comparative   Mortality  from    Phthisis  and  Respiratory 
Diseases  of  Men  in  various  Dust-inhalittg  Occupations. 


Men  twenty-five  to  sixty-five  years  of  age. 


Fishermen  (as  standard). 


Phthisis. 


Lung  diseases. 


Phthisis  and 
lung  diseases. 


Carpenters,  joiners  .    .    . 

Bakers      

Wool-workers 

Cotton-workers 

Cutlers,  scissors-workers 

File-workers 

Masons,  bricklayers     .    . 
Stone  and  slate  quarrymen 
Pottery-makers     .    .    .    .    , 
Cornish  miners     .... 
Coal-miners       


103 
107 
130 

137 
187 
219 
127 
156 
239 
348 
64 


67 

94 

104 

196 
177 
102 

138 
326 
231 
102 


170 
201 

234 

274 

383 
396 
229 
294 
565 
579 
166 


"The  dust  of  ordinary  kinds  of  woods,  such  as  are 
commonly  used  by  carpenters  and  joiners,  appears  to  have 
very  little,  if  any,  injurious  effect  upon  the  air-passages, 
for  the  mortality  of  these  artisans,  both  from  phthisis  and 
from  diseases  of  the  respiratory  organs,  is  below  the 
average  for  males  generally.  The  harder  woods,  how- 
ever, such  as  are  used  by  cabinet-makers,  are  said  to 
give  off  a  much  more  injurious  dust  than  do  the  softer 
woods  used  by  carpenters." 

The  following  tables  are  based  on  statistics  gathered 


266  INDUSTRIAL  HYGIENE. 

from  the  mortality  experience  of  the  industrial  depart- 
ment of  the  Metropolitan  Life  Insurance  Co.,i9iitoi9i3: 

Table  A. — Average  Age  at  Death,  by  Occupation,  Males. 

Average  age 
at  death. 

Bookkeepers  and  office  assistants 36.5 

Enginemen  and  trainmen  (railway) 37.4 

Plumbers,  gas  fitters,  and  steam  fitters 39.8 

Compositors  and  printers 40.2 

Teamsters,  drivers,  and  chauffeurs 42.2 

Saloon  keepers  and  bartenders 42.6 

Machinists 43.9 

Longshoremen  and  stevedores 47.0 

Textile  mill  workers 47.6 

Iron  molders 48.0 

Painters,  paperhangers,  and  varnishers 48.6 

Cigarmakers  and  tobacco  workers 49.5 

Bakers 50.6 

Railway  track  and  yard  workers 50.7 

Coalminers 51.3 

Laborers 52.8 

Masons  and  bricklayers 55.0 

Blacksmiths 55.4 

Farmers  and  farm  laborers 58.5 

All  occupations 47.9 

Table  B. — Average  Age  at  Death,  by  Occupation,  Females. 

Average  age 
at  death. 

Clerks,  bookkeepers,  and  office  assistants 26.1 

Store  clerks  and  saleswomen 28.0 

Textile  mill  workers 33.9 

Dressmakers  and  garment  workers 42.0 

Domestic  servants 49.1 

Housewives  and  housekeepers 53.3 

All  specified  occupations 51. i 

The  figures  for  the  average  age  at  death  of  females 
in  Table  B  are  misleading,  especially  with  regard  to  the 
three  classes  of  occupation  with  the  lowest  average  age 
at  death.  There  is  no  doubt  that  for  these  occupations 
the  low  figures  are  due  to  the  fact  that  women  do  not 
follow  these  occupations  all  their  lives,  but  sooner  or 
later  take  up  the  occupations  included  in  the  other 
three  classes,  in  which,  in  consequence,  the  average 
age  at  death  is  higher. 


INDUSTRIAL  HYGIENE. 


267 


Sommerfeld  ^  gives  the  results  of  a  detailed  study  of  the 
influence  of  occupations  without  and  with  the  formation 
of  dust.  His  calculations  are  based  on  the  results  ob- 
tained in  thirty-eight  Berlin  hospitals.  During  the  time 
over  which  the  investigation  extended  there  were  906,341 
patients  in  these  hospitals,  of  which  number  9761  died. 
Of  the  deaths,  5449  resulted  from  diseases  of  the  respira- 
tory organs,  of  which  number  4675  were  due  to  tuber- 
culosis. 

If  the  occupations  are  divided  into  those  without  and 
those  with  dust,  we  find  marked  differences.  In  the  first 
group  the  death-rate  from  tuberculosis  is  2.39  per  1000; 
in  the  second  group,  5.42  per  1000;  of  1000  deaths,  there 
were  in  the  first  group  381  from  tuberculosis,  in  the  sec- 
ond, 480.  If  these  results  are  compared  with  the  condi- 
tions among  adult  males  in  Berlin,  over  fifteen  years  of 
age,  we  find  that  the  laborers  in  occupations  in  which 
there  is  formation  of  dust  are  affected  not  very  much 
more  unfavorably  than  the  average,  the  laborers  in  the 
occupations  without  dust-formation  far  more  favorably. 


Of  1000  living, 
there  died  of 
tuberculosis — 

Of  1000  deaths, 
there  were  from 
tuberculosis— 

Occupations  without  dust-formati 
Occupations  with  dust-formation 

on  .    .    . 

2.39 
5-42 

381.0 
480.0 

Occupations  with  formation  of — 

I.  Metallic  dust   ...        

5-84 

5-31 

5-55 
7-79 
5-64 
4.42 

470.58 

a.  Copper  dust 

520.5 

b.   Iron  dust 

403.7 

c.   Lead  dust 

501.0 

2.  Organic  dust 

3.  Mineral  dust 

537-04 
403-43 

Average 

5-i6 

478.9 

Adult  males   of  Berlin 
general  population. 

of  same 

age,| 

4-93 

332-3 

Among  the  occupations  in  which  there  is  mineral  dust, 
stone-cutters    and    workers   in   glass  and  porcelain    are 

^  Hygicnische  Rundschau,  Jahrg.  vii.,  S.  44. 


268  INDUSTRIAL  HYGIENE. 

excluded.  When  we  include  these  the  table  is  changed 
in  that  the  occupations  with  mineral  dust  assume  the 
first  place.  Of  1358  stone-cutters,  distributed  among  ten 
places,  Sommerfeld  found  61  deaths,  indicating  a  death- 
rate  of  39  per  1000;  of  497  deaths,  444  were  due  to 
tuberculosis  =:  893.3  P^^  1000.  Among  workers  in  glass 
the  death-rate  from  tuberculosis  was  375  per  1000;  among 
glass-grinders,  500  per  1000;  and  among  workers  in 
porcelain,   600  per   1000. 

A  great  deal  has  been  accomplished  in  recent  years  in 
preventing  the  detrimental  influence  of  the  different  irri- 
tating and  poisonous  gases  and  fumes  evolved  in  certain 
manufacturing  processes.  The  employment  of  special 
ventilating  flues  and  hoods  to  remove  the  poisonous 
gases  obviates,  to  a  large  extent,  the  danger  from  such 
gases,  and  has  rendered  these  occupations  far  more 
healthful. 

In  the  mechanical  trades,  where  irrifating  dusts  are 
most  frequently  encountered,  there  has  also  been  great 
improvement  through  the  introduction  of  special  ap- 
pliances around  each  machine,  whereby  the  dust  is 
exhausted  from  the  work-room  at  the  point  of  produc- 
tion, though  it  is  impossible  to  remove  these  dusts  en- 
tirely. In  the  grinding  of  metals  the  formation  of  dust 
has  been  greatly  diminished  in  many  localities  by  the 
prohibition  of  dry  grinding. 

Moritz  and  Ropke^  report  upon  a  detailed  study  of  the 
hygienic  condition  of  the  metal-grinders  of  Solingen, 
Germany.  The  death-rate  among  the  grinders  from 
1885  to  1895  was  20.6  per  cent.,  as  compared  with  only 
13.6  per  cent,  for  the  remainder  of  the  population.  Of 
100  deaths  in  men  over  fourteen  years  of  age  during  the 
same  time,  72.5  per  cent,  of  the  deaths  among  the 
grinders  were  due  to  tuberculosis;  among  the  remainder 
of  the  population,  only  35.5  per  cent.  On  examination 
of  the  grinders,  only  16  per  cent,  were  found  to  be 
healthy;  5.7  percent,  complained,  but  in  these  no  disease 

1  Zeitschrift  f.  Hygiene,  Bd.   xxxi.,  S.  231. 


INDUSTRIAL  HYGIENE.  269 

was  found;  and  78.3  per  cent,  were  diseased.  Of  those 
over  forty-five  years  of  age,  none  were  found  that  were 
healthy. 

Moritz  and  Ropke  state  that  the  dust  produces  an  irri- 
tation of  the  mucous  membrane  of  the  nose,  resulting  in 
the  formation  of  boils.  There  is  also  a  cutaneous  erup- 
tion and  a  swelling  of  the  nose.  Later,  a  certain  degree 
of  tolerance  is  established,  but  the  mucous  membrane  of 
the  nose  becomes  atrophic.  This  condition  was  found  in 
23.2  per  cent,  of  the  workmen,  as  compared  with  12.2 
percent,  in  the  remainder  of  the  population.  32.2  per 
cent,  suffered  from  chronic  nasal  catarrh,  48.2  percent, 
from  catarrh  of  the  pharynx,  and  12  per  cent,  had  disease 
of  the  lungs.  The  feeling  of  dryness  of  the  throat  leads 
to  the  consumption  of  large  amounts  of  fluid.  The 
effects  of  the  excessive  use  of  alcoholic  beverages  was 
shown  in  11  per  cent,  with  fatty  heart,  and  5.4  per  cent, 
with  fatty  liver.  Rheumatic  affections  were  found  in  4.4 
per  cent. 

The  authors  state  that  in  order  to  prevent  the  forma- 
tion of  dust  wet-grinding  is  to  be  recommended  wher- 
ever possible.  For  the  removal  of  dust  from  the  point 
of  production,  ventilation  apparatus  of  special  construc- 
tion must  be  used;  but,  since  even  with  the  most  perfect 
dust-exhaustion  apparatus  the  penetration  of  dust  into 
the  work-room  is  not  entirely  prevented,  it  is  necessary 
to  remove  the  dust  deposited  on  the  surfaces  in  the  room 
as  frequently  as  possible. 

The  grinders  must  exercise  the  greatest  degree  of 
cleanliness,  not  only  of  the  work-room,  but  also  of  their 
persons,  and  the  introduction  of  shower-baths  into  new 
establishments  is  desirable. 

In  order  to  protect  the  health  of  the  grinders  from  the 
highly  injurious  effects  of  the  dust,  they  should  be  re- 
quired to  breathe  through  the  nose,  and  assume  an 
upright  position  as  much  as  possible. 

The  reduction  of  the  number  of  working-hours  is  also 
recommended,  and  the  observation  of  pauses  about  the 


270  INDUSTRIAL  HYGIENE. 

middle  of  the  forenoon  and  afternoon  to  permit  the  work- 
men to  spend  a  short  time  in  an  atmosphere  free  from 
dust.  A  ten-hour  day  for  adults,  and  an  eight-hour  day 
for  youths,  are  considered  the  maximum. 

The  following  regulations  were  passed  in  1883  con- 
cerning establishments  in  which  metal  goods  are  ground 
and  polished:  The  work-rooms  of  all  new  establishments 
erected,  or  of  extensions  of  old  establishments,  must 
have  a  height  of  at  least  3.5  meters,  the  windows  must 
have  at  least  one-twelfth  the  floor  surface,  and  each 
person  must  be  supplied  with  16  cubic  meters  of  air 
space.  The  floors  must  be  tight,  and  the  walls  must  be 
freshly  painted  or  whitewashed  at  least  once  a  year. 
Clay  floors  in  new  establishments  or  extensions  are  pro- 
hibited, 

Shuler  has  made  a  detailed  study  of  the  hygienic  con- 
dition of  the  millers  of  Switzerland.^  He  studied  the 
sick  lists  of  hospitals,  and  gives  an  analysis  of  108  cases. 
These  were: 

Diseases  of  the  digestive  organs 17 

Diseases  of  the  respiratory  organs 34 

Diseases  of  the  circulatory  organs 3 

Tuberculosis 1 2 

Rheumatism 19 

Diseases  of  the  eyes 4 

Diseases  of  the  skin 19 

Under  the  disea.ses  of  the  respiratory  organs  there  were 
8  cases  of  pneumonia  and  pleurisy,  and  under  the  dis- 
eases of  the  skin  there  were  6  cases  of  itch  and  pedicu- 
losis, and  3  of  eczema. 

Shuler  states  that  if  we  take  certain  disease-groups 
into  consideration,  we  find  in  looo  workmen  the  number 
suffering  from  diseases  of  the  respiratory  organs  dis- 
tributed as  follows:  Millers,  42.3;  cotton-spinners,  47.7; 
embroiderers,  70. 7;  and  workmen  in  mechanical  establish- 
ments, 76.8.  The  number  suffering  from  diseases  of  the 
skin  are  distributed  as  follows:  Millers,  10.2;  cotton- 
spinners,  16.5;  embroiderers,  24.2;  and  mechanics,  32.8. 

'  Deutsche  Vierteljahr.  f.  oeffeiitliche  Gesundheiispjlege,  Bd.  xxix.,  S.  513. 


INDUSTRIAL  HYGIENE. 


271 


The  millers,  who  in  1888  numbered  5412,  had,  in  the 
years  1883  and  1884,  1388  deaths,  at  the  following  ages: 


Age. 


Total   .   .   .   . 
Tuberculosis 


, 

c 

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0 

2  i 

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>> 

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o.E 

§1 

si- 

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0    • 
>..£ 

0  ij 

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>>•£ 

u- 

5 

-C 

■^ 

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[b 

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r^ 

fc. 

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w 

24 

85 

1^0 

200 

320 

360 

267 

6 

29 

46 

59 

63 

26 

8 

Of  the  millers,  16  per  cent,  died  of  pulmonary  tuber- 
culosis, while  in  the  same  years  for  the  total  population 
of  the  cities  of  Switzerland,  with  over  10,000  inhabitants, 
only  14.4  per  cent,  died  of  the  same  disease.  The  death- 
rate  from  tuberculosis  in  the  cities  is  2.95  per  1000,  while 
among  millers  it  is  3.65  per  1000. 

In  the  report  of  Dr.  Kummer,  formerly  Chief  of  the 
Statistical  Bureau,  in  Bertillon's  Encyclopedia  of  Hygiene^ 
on  the  death-rate  from  tuberculosis  in  Switzerland  for  the 
years  1879  to  1882,  the  rate  is  given  for  a  number  of 
different  occupations.  In  1895  Dr.  Crevoisier  reported 
on  the  same  subject  in  the  Swiss  statistical  Zeitschrift 
based  on  material  of  the  statistical  bureau  for  the  years 
1881  to  1890.  These  reports  differ  as  to  the  general 
death-rate  from  tuberculosis,  but  coincide  fairly  well  as 
to  the  death-rate  from  this  disease  for  the  different  trades. 


According  to  Kummer 
Landlords    .    .    . 
Textile-workers  . 
Laborers  (indoors) 
Millers     .    . 
Masons    .    . 
Shoemakers 
Machinists  . 
Butchers  .    . 
Bakers     .    . 
Tailors     .    . 
Carpenters  . 
Book-printers 
Locksmiths 
Stone-cutters 


1-37 
2.14 
2.58 
2.70 
2.74 
2.90 
2.96 
314 
3-33 
3-34 
3-40 

3-65 
4.88 
6.87 


According  to  Crevoisier. 

Landlords 1.80 

Cotton-weavers    .    .    ,    ' 2. 1 5 

Laborers  (indoors) 3.10 

Millers 3.50 

Bakers 3.70 

Silk-weavers 3. 70 

Masons 3. 80 

Shoe-makers 4.00 

Machinists 4.20 

Dyers  and  Printers 4.70 

Cai-penters 4-70 

Book -printers  and  Lithographers  .  6.60 

Locksmiths 7.01 

Stone-cutters 8.00 


27^ 


INDUSTRIAL  HYGIENE. 


The  danger  from  accidents  varies  in  the  different  trades 
and  occupations.  The  Swiss  Secretary  of  Labor  states 
that  among^  looo  laborers  accidents  occur  as  follows: 


Cotton-spinners 22.2 

Millers 28.0 

Paper-manufacturing      31.1 

Carpenters 35.2 

Locksmiths 46.9 


Brewers 66.7 

Masons      80.5 

Smiths 93.1 

Metal-turners I02.i 

Moulders 132.4 


The  Bflfect  of  Anilin  Dyes  and  Nitrobenzine  and 
Its  Compounds. — Dr.  Walter  Maiden  ^  investigated  the 
poisonous  action  of  these  substances  upon  individuals 
whose  occupation  was  concerned  with  constant  handling 
of  these  substances,  as  well  as  the  influence  of  these  sub- 
stances upon  animals. 

In  anilin  workers  the  following  appear  to  be  the  most 
important  points  which  are  shown  by  a  blood  exami- 
nation, (i)  An  increase  in  the  number  of  red  corpuscles 
when  the  amount  of  poison  absorbed  is  small  and  con- 
stant. (2)  A  decrease  in  the  specific  gravity  and  hemo- 
globin of  from  5  per  cent,  to  50  per  cent.  (3)  A  low  color 
index,  showing  that  renovation  of  the  corpuscles  is  pro- 
ceeding more  rapidly  than  the  manufacture  of  hemoglo- 
bin. (4)  Degeneration  or  imperfect  development  of  the 
red  corpuscles  as  shown  by  the  variations  in  size  and  the 
presence  of  corpuscles  containing  basophil  granulations. 
(5)  Abnormal  leukocytic  percentages,  consisting  princip- 
ally in  a  diminution  in  the  polymorphonuclears  and  an 
increase  in  the  other  cells,  particularly  the  lymphocytes, 
eosinophils,  and  mast  cells.  The  following  appear  to  be 
the  most  important  effects  :  (i)  Dinitrobenzol  is  more 
toxic  than  anilin,  and  causes  more  cases  of  acute  poison- 
ing than  any  other  of  the  nitrobenzine  series.  (2)  It 
quickly  affects  the  men  who  work  in  it,  even  within  one 
week.  (3)  The  occurrence  of  red  corpuscles  showing  baso- 
phil granulations  is  the  first  recognizable  sign  in  the  blood 
of  poisoning  by  this  substance.    (4)  The  number  of  red  cor- 

^  Jour,  of  Hyg.,  vol.  vii.,  Oct.,  1907,  p.  672. 


EFFECT  OF  AN  I  LIN  DYES.  273 

puscles  is  reduced  after  a  short  time  by  one  to  one  and  a  half 
million  per  cubic  millimeter.  (5)  The  specific  gravity  and 
hemoglobin  content  are  reduced  in  about  the  same  ratio 
as  the  red  corpuscles  ;  therefore,  the  color  index  is  not 
far  removed  from  unity.  (6)  Some  leukocytosis,  princip- 
ally lymphocytosis,  occurs  in  some  stage  of  chronic  poison- 
ing. (7)  Even  when  there  is  considerable  cyanosis,  the 
presence  of  methemoglobin  cannot  be  detected  spectro- 
scopically  except  in  the  more  severe  cases. 

Maiden  showed  by  animal  experiments  that  anilin, 
whether  injected  subcutaneously  or  inhaled  as  vapor,  very 
rapidly  produces  its  destructive  action  on  the  blood. 

This  action  is  manifested  by  the  following  points  in 
chronological  sequence  :  (i)  Production  of  methemoglo- 
bin in  the  blood.  (2)  Hemolysis  and  destruction  of  red 
corpuscles.  (3)  Rapid  fall  in  the  specific  gravity  and 
hemoglobin  content  of  the  blood,  accompanied  by  a  slight 
reduction  in  the  number  of  leukocytes.  (4)  A  continued 
increase  in  the  number  of  polymorphonuclears,  with  a  cor- 
responding increase  in  the  lymphocytes.  (5)  The  occur- 
rence in  the  red  corpuscles  of  basophil  granules  and  poly- 
chromasia.  (6)  The  occurrence  of  nucleated  red  cells  in 
severe  cases.  (7)  Recovery  after  severe  poisoning  is  rapid 
and  continuous,  and  apparently  no  permanent  disability 
is  entailed. 

These  animal  experiments  corroborate  the  findings  in 
the  blood  of  anilin  and  nitrobenzine  workers  and  enable 
us  to  follow  the  sequence  of  events,  which  appear  to  be 
the  same  in  cases  of  poisoning  by  either  of  these  sub- 
stances, though  they  are  much  more  marked  in  the  case 
of  the  latter.  These  substances  may  gain  access  to  the 
body  by — (i)  inhalation  of  their  vapors;  (2)  absorption 
through  the  skin  ;  (3)  absorption  from  the  alimentary 
canal  after  being  swallowed. 

In  the  less  severe  cases  of  poisoning  in  which  met- 
hemoglobin is  not  present  in  sufficient  amount  to  be 
detected  spectroscopically,  the  changes  which  may  be 
found  in  the  blood  are  sufficiently  characteristic  to  enable 

18 


274  INDUSTRIAL  HYGIENE. 

a  diagnosis  of  aiiilin  or  nitrobenzine  poisoning  to  be 
made.  These  consist  in  :  (i)  A  decrease  in  the  percent- 
age of  hemoglobin  as  estimated  from  the  specific  gravity 
of  the  blood  of  from  5  per  cent,  to  50  per  cent.  (2)  A 
decrease  in  the  number  of  red  corpuscles,  if  the  amount  of 
poison  absorbed  is  considerable  ;  if  the  dose  is  very  small, 
this  decrease  is  not  found,  blood  formation  apparently 
keeping  pace  with  blood  destruction.  (3)  Degeneration 
and  imperfect  development  of  the  red  corpuscles,  as  shown 
by  the  occurrence  of  basophil  granulations,  polychromasia, 
poikilocytosis,  and  variations  in  size.  (4)  The  presence 
of  nucleated  red  corpuscles  in  severe  cases.  (5)  A  decrease 
in  leukocytes,  rapidly  followed  by  an  increase,  the  increase 
being  principally  due  to  the  number  of  lymphocytes. 

The  simultaneous  occurrence  of  all  or  several  of  these 
signs  in  the  blood  enables  a  diagnosis  of  poisoning  by 
anilin  or  nitrobenzine  to  be  made  in  quite  mild  cases. 
Cessation  from  work  for  a  short  time  enables  the  blood  to 
recover  rapidly  from  the  effects  of  poisoning. 

Special  Industrial  Diseases. — The  European  War 
has  brought  into  great  prominence  the  dangers  of 
a  variety  of  industrial  poisonings  that  are  encountered 
in  industrial  establishments,  especially  in  munition 
factories.  These  are  more  especially  risks  from  exposure 
to  lead,  tetrachloride  of  ethane,  nitrous  fumes,  and  cer- 
tain explosives  which  may  cause  fatal  illness,  or  cause 
troublesome  skin  affections  (dermatitis) ,  as  trinitrotoluol, 
tetryl,  fulminate  of  mercury,  and  lubricating  and  cool- 
ing fluids  used  in  metal  turning. 

Lead-poisoning  occurs  from  coming  in  contact  with 
lead  and  its  compounds  in  a  variety  of  processes  in 
munition  factories,  in  smelting  lead  and  spelter,  in 
making  sheet  lead  and  bullets,  in  file-cutting,  in  harden- 
ing and  tempering  metals,  in  tinning,  in  soldering  and 
plumbing,  in  the  manufacture  of  storage-batteries,  in 
the  manufacture  and  use  of  lead  paints  and  red  lead, 
and  in  the  manufacture  of  rubber  and  rubber  goods. 


SPECIAL  INDUSTRIAL  DISEASES.  275 

In  some  of  these  industries  the  lead  gains  access  to  the 
body  principally  by  the  inhalation  of  lead  fumes  and 
dust,  in  others  the  lead  gains  access  to  the  body  princi- 
pally through  the  digestive  tract  by  eating  with  unclean 
hands,  or  by  putting  pipes  or  other  articles  into  the 
mouth  while  the  hands  are  soiled.  A  daily  dose  of  2 
mg.  of  lead  is  likely  to  produce  chronic  poisoning. 

The  inhalation  of  lead  dust  or  fumes  can  be  avoided 
by  preventing  dust  formation  and  by  assuring  that  the 
fumes  are  carried  out  of  the  place  where  the  workmen  per- 
form their  work.  This  is  a  most  difficult  problem,  but 
the  danger  can  be  greatly  diminished  by  localized  exhaust 
ventilation.  An  additional  precaution  should  be  taken 
by  enforcing  the  wearing  of  respirators  by  all  the  work- 
men that  are  exposed  to  lead  dust  or  fumes. 

The  absorption  of  lead  through  the  alimentary  tract 
can  be  diminished  by  instructing  the  men  concerning 
the  danger  of  the  ingestion  of  lead  carried  to  the  mouth 
on  dirty  hands.  Under  no  circumstances  should  the 
workmen  be  allowed  to  eat  a  meal  in  the  workroom,  nor 
without  removing  soiled  outer  garments,  nor  without 
carefully  washing  their  hands.  Special  washing  facili- 
ties should  be  supplied  and  smoking  should  be  prohibited 
in  the  workrooms. 

Trinitrotoluol  is  absorbed  in  the  form  of  dust  and 
fumes  and  is  a  substance  of  increasing  importance 
because  of  the  large  quantities  used  in  munition  factories. 
Every  effort  should  be  made  to  prevent  dust  formation 
and  the  escape  of  the  dust  into  workrooms.  The  fumes 
should  be  carried  off  by  local  exhaust  ventilation.  The 
skin  of  the  workers  should  be  protected  by  wearing  over- 
alls and  leather  gloves.  Especial  care  is  required  to 
prevent  carrying  the  poison  to  the  mouth  by  dirty  hands. 

Tetryl  (tetranitromethyl-anilin)  is  a  highly  poisonous 
explosive  dust  which  may  give  rise  to  eczema.  This 
effect  can  be  prevented  by  avoiding  the  escape  of  dust 


276  INDUSTRIAL  HYGIENE. 

into  the  workroom.  The  wearing  of  Hght  gauze  veils 
by  the  workers  is  also  some  protection  against  this 
poison.  Adequate  faciUties  for  washing  should  be  pro- 
vided. 

Tetrachlorathane  is  a  non-inflammable  liquid  used 
to  dissolve  acetate  of  cellulose,  and  is  used  to  varnish 
the  wings  and  other  parts  of  aeroplanes  to  make  them 
impervious.  The  liquid  volatilizes  and  the  vapor  smells 
hke  chloroform  and  is  a  powerful  anesthetic.  It  is  twice 
as  heavy  as  air  and  tends  to  sink  to  the  floor.  The  in- 
halation of  the  vapor  produces  drowsiness,  loss  of  appe- 
tite, constipation,  and  pains  in  the  stomach.  In  serious 
cases  jaundice,  destruction  of  the  liver  cells,  coma,  and 
death  are  the  effects  produced. 

The  exposure  to  the  vapor  should  be  reduced  to  a 
minimum.  Local  exhaust  ventilation  is  imperative 
and  no  other  work  should  be  carried  on  in  the  same 
room.  Special  attention  should  be  given  to  the  venti- 
lation of  the  workroom. 

Nitrous  fumes  are  encountered  in  munition  facto- 
ries. The  effects  of  these  fumes  are  seen  in  irritating 
cough,  congestion  of  the  bronchioles,  dyspnea,  and  col- 
lapse. 

Workmen  should  be  warned  against  the  danger  of 
inhaling  nitrous  fumes,  and  appliances  should  be  in- 
stalled to  conduct  the  fumes  away  from  the  workmen. 
Ample  ventilation  will  aid  in  reducing  the  danger  to 
the  workmen  from  this  form  of  poisoning.  The  fumes 
are  insidious  in  their  action  and  consequently  may  not 
be  noticed  until  a  fatal  dose  has  been  inspired  unless 
the  workmen  are  properly  warned  beforehand. 

Influence  of  the  I^engfth  of  the  Working-day  on 
the  Health  of  the  I/aborers. — Dr.  B.  Roth,4n  a  paper 
on  this  subject,  makes  the  following  statements : 

'^Deutsche    Vierteljahr.  /.    oefentliche    Cesundheitspflege,   Bd.   xxvii.,   S. 

277. 


LENGTH  OF  WORKING-DA  V  OF  LABORERS.    277 

"  I.  The  length  of  the  working-day  must  be  shorter 
the  greater  the  amount  of  mental  or  physical  energy  re- 
quired, or  the  greater  the  danger  from  the  industrial  oc- 
cupation. 

"  2.  The  length  of  the  working-period  must  be  shorter 
the  less  developed  and  the  less  resistant  the  organism  of 
the  laborer.  ^ 

"3.  Women  and  youths  must  be  excluded  from  all 
work  in  which  great  physical  energy  is  required  ;  also 
from  industries  in  which  their  health  may  be  affected 
by  the  action  of  poisonous  substances  or  dust,  or  which 
require  special  and  continued  attention. 

"4.  Laborers  of  eighteen  years  of  age  are  to  be  in- 
cluded in  the  protected  class  of  fourteen  to  sixteen  years 
of  age. 

"5.  Even  where  the  factory-work  does  not  exert  a 
direct  effect  upon  the  mental  or  physical  condition,  and 
is  not  accompanied  with  particular  danger  from  accident, 
the  length  of  day  must  not  exceed  a  definite  number  of 
hours. 

"  If  a  universal  maximum  is  to  be  established,  then  a 
ten-hour  working-day  may  be  established  in  general  when 
the  existing  conditions  are  favorable,  and  a  longer  work- 
ing-period may  not  be  allowed  either  in  the  interest  of 
the  laborers  or  their  employers.  Exception  must  be 
made  in  those  occupations  in  which  no  definite  working- 
day  can  be  established. 

The  following  tables  do  not  indicate  any  marked  de- 
crease in  the  number  of  sick-days  per  laborer  after  a  re- 
duction in  the  length  of  the  working-day  from  nine  to 
eight  hours  : 

Male  Laborers. 


Year. 


1893 


Length  of 
working- 
day. 

Average 
number 
working. 

Number  of 
working- 
days. 

Number 
of  sick- 
days. 

Percent, 
of  work- 
ing-days. 

Sick-days 

per 

laborer. 

9  hours. 
9       " 
9      " 

114 
141 
116 

35,568 
43,992 
36,192 

726 
808 
478 

2.04 
1.84 
1.32 

6-37 
5-73 
41 

8       " 

97 

30,264 

256 

0.84 

2.64 

8      " 

105 

32,760 

660 

2.01 

6.2 

'%  hours  after 
April  I. 


278 


INDUSTRIAL  HYGIENE. 
Female  Laborers. 


Year. 


Length  of 
working- 
day. 

Average 
number 
working. 

Number  of 
working- 
days. 

Number 
of  sick- 
days. 

Per  cent, 
of  work- 
ing-days. 

Sick-days 

per 
laborer. 

9  hours. 
9       " 
9       " 

225 
236 
247 

70,200 
73,632 
77,064 

1286 
1942 
1007 

1.83 
2.63 
1.30 

5-71 
8.2 
4.08 

8       " 

230 

71,760 

1205 

1. 61 

S-2 

8      " 

204 

63,684 

1404 

2.20 

6.9 

'Z  hours  after 
April  I. 


"6.  The  system  of  working  overtime  should  be 
earnestly  discouraged. 

"  7.  For  youthful  workers  a  forenoon  and  an  afternoon 
pause  are  necessary  aside  from  the  midday  intermission. 

"  For  adult  laborers  these  special  pauses  are  required 
when  the  midday  pause  is  only  one  hour,  and  when  the 
working  period  of  the  forenoon  and  afternoon  exceeds 
four  hours,  or  the  total  working-day  exceeds  eight  hours." 

I/ighting  of  Industrial  Establishments.  —  The 
hygienic  requirements  in  the  artificial  lighting  of  indus- 
trial establishments  are  given  very  succinctly  by  Eris- 
mann,  in  a  paper  on  "Artificial  Lighting,  with  Special 
Reference  to  Distrib.ution  of  Light,"  ^  in  which  he 
states  that:  "  Hygiene  makes  the  following  demands  on 
the  lighting  technic: 

"  I.  The  quantity  of  light  falling  upon  each  worl^- 
place — the  so-called  degree  of  light — as  well  as  the 
brightness  of  the  surface,  must  be  sufficiently  great. 
For  coarser  work  on  good  reflecting  surfaces  10  meter- 
candles  are  sufficient;  for  finer  work  and  with  unfavorable 
reflection  conditions,  on  the  other  hand,  at  least  25  to  30 
meter-candles  are  required.  The  quantity  of  light  is  to 
be  measured  photometrically. 

"  2.  The  pollution  of  the  air  by  the  products  of  com- 
plete or  incomplete  combustion  of  the  illuminating- 
material  shall  be  as  low  as  possible.  The  purity  of  the 
illuminating-material  must  be  insisted  upon.  And  since 
with  the  increased  amount  consumed  the  absolute  quan- 
tity of  the   combustion-point   is   increased,    under   like 

'^Deutsche  Vierteljahr.f.  oeffentliche  Gesundheitspflege,  Bd.  xxii.,  S.  11. 


LIGHTING  OF  INDUSTRIAL  ESTABLISHMENTS.  279 

conditions  that  form  of  illumination  is  to  be  desired  in 
which  the  total  consumption  of  illuminating-material 
per  degree  of  light  is  lowest. 

"  3.  Artificial  lighting  must  not  produce  any  percepti- 
ble increase  in  the  temperature  of  the  illuminated  room; 
therefore  the  heating  effect  of  the  source  of  light  must 
be  as  low  as  possible.  In  systems  of  illumination  in  which 
large  quantities  of  hot  combustible  gases  are  produced, 
these  must  be  efficiently  removed.  To  lessen  the  heat- 
production  through  hot  gases,  it  is  important  that  as 
large  an  amount  as  possible  of  the  energy  produced  is 
converted  into  light,  and  in  consequence  that  the  con- 
sumption of  illuminating-material  in  proportion  to  the 
brightness  of  the  flame  is  as  low  as  possible. 

"4.  The  heat-rays  of  the  source  of  light  must  not 
produce  any  discomfort.  The  discomfort  can  be  di- 
minished by  increasing  the  distance  between  the  heated 
body  and  the  persons  in  the  room.  Since,  however,  the 
amount  of  light  is  rapidly  diminished  by  this  means,  the 
conditions  for  diminishing  the  discomfort  from  heat-rays 
must  be  sought  in  the  system  of  illumination  itself; 
therefore  such  sources  of  light  are  to  be  selected  in  which 
the  caloric  equivalent  of  the  non-luminous  portion  of  the 
flame  is  as  low  as  possible.  The  construction  of  the 
burners  or  the  lighting  apparatus  must  be  of  such  a  na- 
ture that  the  lowest  possible  radiating  effect  is  obtained. 
As  the  best  source  of  light,  other  conditions  being  the 
same,  must  be  considered  that  in  which  the  heat-radia- 
tion per  candle-power  of  light  is  the  lowest.  The  heat- 
radiation  of  an  ideal  source  of  light  should  be  extremely 
small.  From  this  standpoint  the  color  of  the  light  is  not 
without  significance,  since  a  light  which  possesses  many 
red  rays  indicates,  in  general,  a  high,  and  a  light  with 
principally  green  and  blue,  on  the  other  hand,  a  low 
heat-radiation. 

"  5.  Sources  of  light  that  possess  a  high  reflecting 
power,  in  which  a  large  amount  of  light  falls  upon  a  unit 
of  surface,  must  be  shaded  from  the  eyes  or  weakened  in 
some  way. 


28o  INDUSTRIAL  HYGIENE. 

"  6.  Flickering  of  the  light  and  decrease  in  the  inten- 
sity of  the  light  are  to  be  avoided  in  the  illumination  of 
rooms.  A  uniform,  steady  light  is  everywhere  to  be 
desired,  and  is  absolutely  necessary  where  work  is  carried 
on  in  which  the  eyes  are  used  for  a  long  time,  or  to  a 
large  extent  (school-rooms,  certain  factories,  etc.). 

"7.  The  dangers — poisoning,  explosion,  fire,  electric 
shock — to  which  the  consumer  or  the  public  is  exposed 
in  general  through  installation  or  conduction  of  illumin- 
ating-arrangements, shall  be  as  small  as  possible. 

"8.  Of  not  less  importance,  and  for  certain  rooms 
(school)  of  more  importance  than  the  supplying  of  as 
large  a  quantity  of  light  as  possible,  are  the  uniform  dis- 
tribution of  the  light  and  the  reduction  of  shadow-pro- 
duction. This  requirement  can  be  fulfilled  in  direct 
illumination  only  under  especial  circumstances.  The 
end  is  most  simply  and  surely  attained  by  the  use  of  indi- 
rect (electric)  light.  For  school-rooms  this  is  the  only 
mode  of  illumination  which  meets  all  the  hygienic 
requirements.  It  can  also  yield  very  good  results  in 
factories.  The  discomfort  from  heat-radiation  is  entirely 
removed,  because  the  source  of  light  is  raised  high  above 
the  heads  of  the  occupants. 

"A  combination  of  direct  light  with  indirect,  by 
means  of  white-glass  reflectors,  is  not  to  be  recom- 
mended where  there  is  shadow-formation  (as  in  writing), 
and  metal  reflectors  are  to  be  preferred." 


CHAPTER    XII. 
SCHOOL    HYGIENE. 

A  LARGE  proportion  of  the  ill  health  of  a  community  is 
found  in  children  of  school  age,  and  since  such  a  high 
percentage  of  this  ill  health  can  be  prevented,  it  is  neces- 
sary to  treat  briefly  the  subject  of  school  hygiene. 

Site,  or  l/ocation,  with  Reference  to  Drainage 
Capacity  of  the  Soil. — In  school  architecture  a  ques- 
tion of  primary  importance,  the  consideration  of  which 
is  frequently  neglected,  is  that  of  location  with  regard  to 
the  nature  of  the  soil  and  its  drainage  capacity.  Satis- 
factory sanitary  arrangements  can  rarely  be  secured  in 
any  building  unless  the  site  of  the  building  is  carefully 
selected  with  regard  to  the  drainage  capacity  of  the  soil. 
The  soil  structure  as  regards  the  preponderance  of  defin- 
ite-sized grains,  coarse  or  fine,  influences  the  drainage 
capacity,  and  consequently  the  healthfulness  of  the  site. 
The  amount  of  slope  and  the  proximity  of  streams, 
either  surface  or  underground,  also  influence  the  char- 
acter of  the  soil.  For  these  reasons  it  is  of  primary 
importance  that  the  site  selected  for  a  school-building 
shall  be  of  such  a  nature  as  to  afford  the  very  best  facili- 
ties for  drainage,  not  only  for  refuse  and  excreta  collected 
in  the  building,  but  for  surface-  and  rain-water  flowing 
over  the  soil.  Whenever  the  soil  of  the  site  is  not  per- 
fectly dry,  it  should  first  be  underdrained. 

Parkes  states  that  the  conditions  which  insure  healthy 
habitations  are: 

1.  A  site  that  is  dry  and  not  malarious,  and  an  aspect 
which  gives  light  and  cheerfulness. 

2.  A  pure  supply  and   proper   removal  of  water,  by 

281 


282  >  SCHOOL  HYGIENE. 

means  of  wliich  perfect  cleanliness  of  all  parts  of  the 
house  can  be  secured. 

3.  A  system  of  immediate  and  perfect  sewage  removal, 
which  renders  it  impossible  that  the  air  or  water  shall  be 
contaminated  from  excreta. 

4.  A  system  of  ventilation  which  carries  off  all  respira- 
tory impurities. 

5.  A  condition  of  house  construction  which  insures 
perfect  dryness  of  the  foundation,  walls,  and  roof. 

Structure  of  Walls. — Having  selected  a  proper  site 
for  the  building,  the  nature  of  the  building  is  of  consid- 
erable importance.  The  building  itself  should  be  de- 
tached, so  as  to  obtain  an  abundant  supply  of  fresh  air 
and  the  greatest  amount  of  light.  The  character  of  the 
materials  composing  the  walls  and  the  thickness  of  the 
walls,  the  number  of  layers  composing  them,  all  have  an 
important  influence  on  the  character  of  the  building. 
The  walls  should  be  rendered  impervious  to  moisture, 
and  it  is  preferable,  therefore,  to  have  double  walls  with 
an  air  space  between  the  inner  and  outer  surface.  The 
materials  employed  in  constructing  the  walls  will  be  gov- 
erned by  circumstances,  and  their  nature  is  not  of  great 
importance  if  they  are  properly  used.  Stone  walls  are 
usually  somewhat  damp,  but  can  be  rendered  perfectly 
dry  by  allowing  an  air  space  between  the  inner  and  outer 
layers. 

Cubic  Space  and  Floor  Space.— Cubic  Space. — From 
calculations  made  by  Prof.  Parkes  and  Dr.  de  Chaumont, 
the  amount  of  air  required  for  each  adult  per  hour,  in 
order  to  maintain  a  certain  degree  of  purity  in  the  atmos- 
phere, is  85  cubic  meters.  The  respiratory  impurity 
added  to  the  air  will,  of  course,  be  less  with  children  than 
adults,  consequently  the  amount  of  air  required  to  main- 
tain the  standard  of  purity  will  be  less.  Though  children 
evolve  less  carbon  dioxid  in  a  given  time  than  adults,  yet 
relatively  for  their  body-weight  they  expire  more.  In 
fixing  a  standard  for  schools,  the  age  of  the  children 
ousfht  also  to  be  considered  ;  the  average  amount  of  air  re- 


CUBIC  SPACE  AND  FLOOR  SPACE.  283 

quired  being  about  55  cubic  meters  per  hour.  Parkes  says 
that  it  is  highly  desirable  that  some  general  agreement 
should  be  arrived  at  as  to  the  amount  of  air  necessary, 
even  if  it  be  admitted  that  the  desired  amount  cannot 
always  be  obtained.  If  we  adopt  the  following  amounts 
of  carbon  dioxid  as  being  evolved  during  an  hour  in 
repose,  we  shall  not  be  far  from  the  probable  truth: 

Adult  males  .  (say  70  kilograms  weight),  0.72  cubic  foot  =  20        liters. 
Adult  females  (  "    51         "  "        ),  0.6  "        =17  " 

Children    •    •  (   "    35         "  "        ),  0.4  "         =  11.25     " 

Average  of  a  mixed  assembly      ....    0.6  "         =17  " 

The  amount  of  fresh  air  that  must  be  supplied  in  order 
to  prevent  the  impurity  due  to  products  of  respiration 
exceeding  a  particular  limit,  is  measured  by  the  quantity 
of  carbon  dioxid  present  in  excess  over  that  in  external 
air,  according  to  either  of  the  standards  in  use,  and  may 

be  calculated  from  the  formula  -  =  fl',   where  e  =  amount 

r 

of  carbon  dioxid  expired  in  liters  per  head  per  hour; 
r  =  admissible  limit  of  carbon  dioxid  due  to  respiratory 
impurity,  stated  per  liter;  ^=  delivery  of  fresh  air  per 
liead  in  cubic  meters. 

Under  these  conditions  the  amount  of  fresh  air  to  be 
supplied  in  health  during  repose  ought  to  be: 

For  adult  males     3600  cubic  feet  per  head  per  hour  =  102  cubic  meters. 
For  adult  females  3000  "  "  "         =    85       "         " 

For  children  .    .    2000  "  "  "         =    57       "         " 

For     a     mixed 

assembly    .    .    3000  "  "  "         =    85       "         " 

The  law  of  Massachusetts  requires  that  each  occupant  of 
a  school-room  receive  a  quota  of  850  liters  of  air  per  minute. 
If  this  is  taken  as  the  basis  for  the  minimum  amount  of 
air  required  by  each  child,  and  we  require  further  that 
the  air  be  changed  but  three  times  each  hour,  then  the 
minimum  amount  of  cubic  space  allowable  for  each  child 
is  17  cubic  meters.  This  is  slightly  lower  than  the  theo- 
Tetical  amount,  as  shown  by  the  calculations  of  Parkes, 


284  SCHOOL  HYGIENE. 

but  it  is  far  in  excess  of  the  amount  of  space  usually  sup- 
plied in  common  schools. 

When  the  air  of  a  room  is  changed  more  frequently 
than  three  times  an  hour,  there  is  always  more  or  less 
draft  in  some  portions  of  the  room,  and  for  this  reason 
the  minimum  amount  of  space  allowed  should  be  17 
cubic  meters.  Even  with  this  amount  of  cubic  space 
it  is  impossible  to  keep  the  air  of  rooms  of  the  same 
purity  as  outside  air,  owing  to  the  gases  given  off"  during 
respiration.  For  this  reason  a  certain  amount  of  respir- 
atory impurity,  as  it  is  called,  is  permissible  in  well- 
ventilated  rooms.  With  the  outside  air  containing  0.4 
part  in  1000  of  carbon  dioxid,  the  additional  amount  per- 
missible as  coming  from  respiration  is  o.  2  part  in  1000, 
making  a  total  amount  of  carbon  dioxid  in  the  air  of  0.6 
part  in  1000.  It  should  be  our  aim  in  the  ventilation  of 
school-rooms  to  maintain  the  respiratory  impurity  at  this 
low  standard,  and  this  it  is  possible  to  do  if  the  initial  cubic 
space  is  sufficient — say  17  cubic  meters — and  we  have 
reliable  mechanical  means  for  introducing  the  requisite 
amount  of  fresh  air  each  hour.  If  the  cubic  space  is  less, 
or  the  arrangements  for  the  introduction  of  fresh  air  are 
imperfect,  it  is  impossible  to  have  perfect  ventilation  and 
pure  air.  It  is,  therefore,  merely  a  matter  of  choice  on 
our  part  whether  we  will  elect  to  have  efficient  ventilation 
or  not.  It  can  be  obtained  by  making  the  necessary 
expenditure.     Without  this  it  is  impossible  to  obtain  it. 

Floor  Space. — Each  child  should  have  a  floor  space  of 
at  least  4. 25  square  meters.  This  amount  of  floor  space, 
when  the  height  of  the  room  is  4  meters,  will  give  each 
child  a  minimum  cubic  space  of  17  cubic  meters.  The 
amount  of  floor  space  is  an  important  factor,  inasmuch 
as  it  is  brought  into  relation  with  the  height  of  the 
room. 

Relation  of  Window  Space  to  Cubic  Space.— In 
fixing  the  height  of  stories,  when  not  governed  by  fhe 
amount  to  be  expended,  the  height  of  the  basement 
should  be  2.8  to  3  meters.       The  first   story  should  be 


LIGHTING.  285 

3.9  and  the  second  story  3.8  meters  in  height.  Light  in 
rooms  of  the  second  story  is  always  superior  to  that  of  the 
first,  consequently  the  increased  height  of  the  first  storv'. 
There  is  also  usually  an  increase  of  glass  surface  pro- 
vided for  the  first  story  to  equalize  the  difference  in  light. 
The  window  heads  should  be  finished  to  the  top,  so  that 
no  shadow  can  be  thrown  on  the  ceiling.  The  sills  of 
windows  should  be  i  meter  from  the  floor.  The  propor- 
tion of  light  to  floor  of  class-rooms  should  never  be  less 
than  I  square  meter  of  glass  surface  to  6  square  meters 
of  floor  surface,  for  rooms  10  meters  wide,  lighted  from 
only  one  side.  Within  the  limits  of  a  city,  where  the 
adjoining  buildings  are  about  6  meters  from  the  exterior 
walls,  this  proportion  should  be  increased  to  i  to  5.  The 
length  of  the  school-room  should  not  be  over  15  meters, 
and  the  width  not  over  10  meters,  while  the  height 
should  be  at  least  3.8  meters. 

I/igiiting-. — The  lighting  of  school-buildings  is  a  mat- 
ter of  very  great  importance.  The  windows  should  never 
be  in  the  front  of  the  room,  only  at  the  sides  and  rear. 
It  is  preferable  to  have  them  on  the  left  side  of  the  room, 
so  as  to  have  the  light  falling  over  the  left  shoulder  of 
the  pupil.  The  windows  should  be  provided  with  shades 
or  blinds,  so  that  direct  sunlight  can  be  excluded  as  re- 
quired. 

As  the  sense  of  sight  is  the  chief  medium  of  educa- 
tion, it  is  hardly  possible  to  overestimate  the  importance 
and  necessity  for  carefully  observing  the  management  of 
light  in  school-rooms.  It  has  been  positively  established 
by  careful  and  extensive  statistics  that  myopia  is  most 
frequently,  if  not  exclusively,  developed  during  school- 
life.  This  is  due  partly  to  the  fact  that  the  eye  during 
this  period  of  growth  is  more  liable  to  change  in  form, 
and  partly  to  the  fact  that  children  have  much  stronger 
power  of  accommodation  than  adults,  and  therefore  hold 
objects  more  closely  to  the  eye.  The  book  or  paper 
should  never  be  closer  to  the  eye  than  25  centimeters. 
If  there  is  myopia  sufficient  to  prevent  the  letters  from 


286  SCHOOL  HYGIENE. 

being  distinct  at  this  distance,  it  is  better  to  wear  glasses 
in  the  study-room.  In  erecting  public  schools  it  involves 
a  little  extra  expense  to  provide  windows  of  sufficient 
size.  ■  Architectural  beauty  ought  to  be  a  secondary 
consideration  where  such  grave  practical  interests  are 
involved.  Dr.  Cohn  maintains  that  a  school-room  can- 
not have  too  much  light,  and  recommends  the  very 
large  proportion  of  i  square  meter  of  window  glass  for 
evefy  square  meter  of  floor  surface,  and  that  less  than, 
about  one-half  of  this  proportion  should  never  in  any 
case  be  allowed.  The  arrangement  that  Mr.  Eiberich 
advocates  is  to  have  the  class-rooms  of  oblong  shape,  the 
windows  being  on  one  of  the  long  sides  and  the  desks 
arranged  parallel  to  the  short  walls,  so  that  the  light 
falls  from  the  left  side. 

The  Position  of  Blackboards. —  The  blackboards 
should  be  on  the  inner  wall  of  the  room,  where  the 
greatest  amount  of  light  will  fall  upon  them,  and  they 
should  be  of  a  dull-black  color.  The  principal  cause  of 
defective  eyesight  in  school-children  is  no  doubt  traceable 
to  improper  lighting  of  the  room,  which  may  be  either 
excessive  light  or  deficient  light,  or  light  coming  from 
the  wrong  direction.  The  position  of  the  blackboards 
and  their  frequent  use  for  copying  exercises,  while  the 
child  is  at  its  desk,  require  rapid  changes  in  the  accom- 
modation, which  is  also  a  factor  in  producing  defective 
eyesight.  Another  factor,  independent  of  the  arrange- 
ment of  the  school-room,  is  the  use  of  books  printed  with 
defective  type  or  with  too  small  a  type. 

Corridors,  Cloak-rooms,  and  Wardrobes. — The  cor- 
ridors should  be  without  obstruction,  and  never  less  than 
2.4  meters,  preferably  3  meters,  wide.  The  stairways 
should  be  1.8  meters  wide,  and  each  flight  should  be 
broken  with  a  landing.  These  stairs  should  be  as  near 
to  the  exit  as  possible,  and  equally  placed  at  each  end  of 
the  building.  The  walls  should  be  of  brick,  and  finished 
in  white  enamelled  brick  or  white  enamelled  paint.  Wall- 
paper should  never  be  allowed  in  school-rooms,  because 


VENTILA  TION.  287 

of  the  difficulty  of  maintaining  it  in  a  proper  sanitary 
condition. 

As  contagion  is  most  likely  to  occur  from  garments, 
which,  if  porous',  absorb  and  transport  gases,  bacteria, 
etc.,  it  is  necessary  to  have  two  wardrobes  properly  ar- 
ransfed  on  each  floor,  one  for  each  sex.  The  latest  im- 
proved  wardrobes,  set  up  in  separate  rooms  or  in  the 
corridors,  either  in  the  basement  or  on  each  story,  are 
made  with  separate  stalls  of  channel  iron.  At  the  bottom 
is  a  shelf  for  rubbers,  two  rings  and  cups  for  umbrellas, 
with  hangings  on  each  side.  The  best  place  for  ward- 
robes is  in  each  corridor,  provided  it  is  wide  enough. 
Wardrobes  seem  to  be  the  most  difficult  problem  of  school 
sanitation,  there  being  many  advantages  in  the  method 
of  placing  them  in  wide  corridors,  unless  special  rooms 
can  be  provided,  with  thorough  circulation  of  fresh  air. 
The  advantage  of  having  wardrobes  in  the  corridors  is 
that  the  teacher  in  charge  of  that  floor  maintains  the 
discipline,  and  there  will  be  no  travelling  up  and  down 
to  the  basement. 

Ventilation. — With  regard  to  the  introduction  of 
fresh  air,  probably  the  most  satisfactory  arrangement  for 
a  school-building  is  that  by  means  of  indirect  heating, 
where  the  air  required  for  ventilation  is  brought  in  at  the 
desired  temperature,  thus  maintaining  the  temperature 
of  the  room,  while  the  purity  of  the  atmosphere  is  secured 
at  the  same  time. 

As  to  the  best  method  to  introduce  the  requisite  amount 
of  air  into  school-buildings,  numerous  systems  of  ven- 
tilation and  heating  are  in  use,  several  of  which  give 
satisfactory  results,  if  properly  constructed.  If  the 
building  contains  as  many  as  eight  or  ten  rooms,  and  is 
two  or  three  stories  in  height,  it  is  impossible  to  ventilate 
it  satisfactorily  without  the  introduction  of  fans  to  assist 
in  either  propelling  the  incoming  air  or  extracting  the 
foul  air  of  the  rooms.  It  is  customary*  to  have  one  of 
these  blowers  in  the  shaft  through  which  fresh  air,  already 
heated  by  passing  over  steam  coils,  makes  its  entrance 


288  SCHOOL  HYGIENE. 

into  the  room  to  be  warmed  and  ventilated.  These  shafts 
are  usually  supplied  with  a  by-pass  valve,  which  is  under 
the  control  of  a  thermo-regulator,  so  that  the  supply  of 
air  is  kept  at  a  definite  temperature  automatically.  As 
soon  as  the  temperature  rises  above  the  desired  point,  the 
thermo-regulator  cuts  off  the  supply  of  heated  air,  and 
allows  cold  air  to  enter  and  mix  with  the  heated  air. 
This  not  only  facilitates  the  proper  ventilation  of  the 
rooms,  but  likewise  economizes  the  amount  of  fuel  used. 
By  means  of  fans  it  is  possible  to  introduce  a  definite 
amount  of  air  in  a  definite  period  of  time,  the  entire  cir- 
culation of  air  being  under  control. 

In  this  method  of  ventilation  and  heating  it  is  possible 
to  place  the  intake  of  fresh  air  at  such  a  point  as  to  pre- 
vent some  of  the  grosser  atmospheric  impurities  from 
gaining  access  to  the  building.  This  point  of  intake 
may  vary  according  to  the  location  of  the  building; 
ordinarily,  it  should  be  at  least  2  or  3  meters  above 
ground.  It  may  be  over  the  roof  of  the  house,  if  it  is 
found  that  at  that  point  the  air  is  purer  than  at  a  lower 
level.  It  is  also  possible  by  this  method  of  ventilation 
and  heating  to  filter  the  air,  in  order  to  remove  the  grosser 
dust  particles,  b}^  passing  it  through  a  screen  over  which 
a  constant  stream  of  water  is  flowing.  It  is  also  possible 
to  regulate  the  humidity  of  the  air,  to  some  extent, 
through  this  method  of  filtration,  the  air  taking  up  some 
moisture  in  passing  over  the  screen. 

Heating. — Heating  may  be  accomplished  either  by 
what  is  known  as  direct  heating,  as  by  use  of  a  stove  or 
open  fireplace,  or  through  steam  or  hot-water  radiators 
in  the  room.  Or  it  may  be  by  what  is  known  as  in- 
direct heating,  where  the  radiating  surface  is  in  some 
other  portion  of  the  building,  and  the  rooms  are  heated 
by  bringing  in  air  that  is  warmed  by  passing  over  steam 
or  hot-water  coils.  Where  a  s^^stem  of  direct  heating  is 
employed,  whether  with  steam  or  hot  water,  the  ca- 
pacity of  the  heating  plant  should  be  adapted  to  meet 
the  requirements  placed  upon  it.     Mr.  William  J.  Bald- 


WATER-SUPPLY  AND  SEWAGE  DISPOSAL.    289 

win,  in  his  Steam  Heating  Data^  states  that  the  question 
of  condensation  of  steam  receives  the  first  consideration 
in  making  calculations  for  the  heating  of  a  building.  If 
asked  the  question  why  condensation  is  considered  first, 
he  would  reply  that  "  it  furnishes  us  with  the  first  item 
of  data  on  which  to  base  our  calculations.  For  instance, 
when  we  find  the  amount  of  cooling  or  condensation  that 
is  to  take  place  within  a  building  in  the  coldest  weather, 
we  then  know  the  amount  of  water  it  is  necessary  to 
evaporate  to  do  this  work.  Having  the  amount  of  water 
evaporated,  we  can  then  obtain,  in  the  order  we  please,  the 
size  of  boiler  necessary  to  evaporate  the  water,  the  amount 
of  coal  or  other  fuel  that  will  evaporate  that  amount  of 
water,  the  size  of  the  grate  on  which  to  burn  the  coal, 
the  size  and  height  of  chimney  necessary  to  supply  air 
for  combustion,  the  size  of  the  radiators  necessary  to 
condense  the  steam,  the  size  of  pipes  necessary  to  convev 
steam  or  hot  water  to  the  radiators,  and  all  other  attend- 
ant data  which  will  develop  as  we  proceed." 

Water-supply  and  Sewage  Disposal. — The  building 
should  have  an  abundant  supply  of  pure  water,  so  as  to 
insure  against  the  diseases  ordinarily  carried  by  water; 
also  to  facilitate  the  maintaining  of  strict  cleanliness 
among  the  children  in  the  building.  The  children  should 
be  provided  with  individual  drinking-cups  or  paper  cups 
should  be  supplied  free  of  charge.  In  this  way  the  pos- 
sibility of  the  more  or  less  direct  transmission  of  disease- 
producing  bacteria  is  reduced.  Drinking-fountains  also 
serve  to  limit  the  dissemination  of  the  infectious  diseases. 
It  is  also  necessary  to  devise  some  method  for  the  disposal 
of  the  sewage,  in  the  absence  of  a  system  of  sewers.  This 
becomes  a  separate  question  in  different  localities.  In 
some  instances,  where  the  price  of  land  permits,  it  will 
probably  be  safest  and  cheapest  in  the  end  to  have  some 
form  of  surface  irrigation.  Where  the  price  of  land  does 
not  permit  this  method  of  disposal,  it  may  be  necessary 
to  resort  to  properly  constructed  cesspools  or  some  of  the 
modern  methods  of  purification. 

19 


290  SCHOOL  HYGIENE. 

Water-closets  and  I/atrines. — Where  there  are  no 
sewers  we  unhesitatingly  use  the  closets ;  but  these 
should  discharge  into  specially  constructed  tanks  or  cess- 
pools, so  that  the  sewage  may  be  disposed  of  in  a  sanitary 
manner.  There  should  be  no  connection  of  any  kind 
between  the  class-rooms  and  the  water-closets.  In  no  case 
should  wastes  of  sinks  be  discharged  into  the  vaults.  The 
wastes  should  enter  a  cesspool,  preferably  a  double  cesspool 
— with  a  tight  compartment  for  solids  and  a  leeching  one 
for  liquids.  The  best  urinal  is  of  slate,  with  the  dry-earth 
system.  There  should  be  a  connecting  waste  from  the 
trough  and  a  connection  with  the  cesspool  drain.  Water- 
closets  for  the  pupils'  use,  where  there  is  water  carriage, 
should  be  with  automatic  seats.  Thick  porcelain  slabs, 
with  backs,  are  the  best  and  cheapest  devices  for  drinking- 
fountains  in  the  corridors.  The  plumbing  of  the  building 
should  be  the  best  obtainable,  with  tight  joints  and  as  few 
bends  in  the  pipes  as  possible;  and  these  pipes  should  be 
properly  ventilated  by  means  of  an  open  trap  outside  the 
building,  between  it  and  the  sewer,  and  by  carrying  the 
other  end  of  the  soil  pipe  up  over  the  roof  of  the  build- 
ing, of  the  same  diameter  throughout.  All  the  traps  of 
the  water-closets  and  sinks  must  be  back-aired,  in  order 
to  insure  against  the  production  of  foul  odors  in  the 
un ventilated  ends  of  the  pipe;  and  also  to  prevent  the 
unsealing  of  these  traps. 

Each  story  of  the  school-building  should  be  provided 
with  suitable  water-closets,  with  automatic  flushing  ar- 
rangements. These  toilet-rooms  should  also  be  provided 
with  sinks,  so  as  to  facilitate  maintaining  a  proper  degree 
of  cleanliness  of  the  hands  and  persons  of  the  pupils. 
The  expense  of  soap  and  towels  to  the  community  is  a 
small  one  compared  with  the  detriment  occasioned  by 
permitting  the  children  to  come  in  contact  with  each 
other  when  some  of  them  are  not  as  cleanly  as  they 
should  be. 

Desks  and  Seats. — The  height  of  the  seat  must  cor- 
respond with  the  length  of  the  pupil's  legs  below  the 


DESK'S  AND  SEA  TS. 


291 


Fig.  52. — Comparative  diagram  showing  {a)  the  proper  position  at  a 
desk;  {b)  the  position  when  the  desk  is  too  low;  and  {c)  the  position  when 
the  desk  is  too  high  (after  Cohn). 


w 


Fig.  53. — Position  assumed  in  writing  with  the  desk  too  high. 


292 


SCHOOL  HYGIENE. 


knees.  The  seat  may  be  horizontal  or  slightly  curved. 
The  back  of  the  seat  should  be  composed  of  an  upper 
concave  portion  and  of  a  lower  convex  portion,  so  as  to 
conform  to  the  back  of  the  pupil,  and  it  should  be  of  suffi- 
cient height  to  support  properly  the  pupil's  back.  The 
■writing  desk  should  have  an  inclination  of  about  15  de- 
grees. The  desk  should  be  fitted  to  the  size  of  each 
pupil.  The  prevalence  of  lateral  curvature  of  the  spine 
in  children  is  traceable  to  the  use  of  desks  that  are  en- 
tirely too  high  or  too  low  (Figs.  53  and  54). 

Defects  in  School-buildings. — During  1896-97  a 
committee  of  the  Women's  Health  Protective  Association 
of  Philadelphia,  with  the  assistance  of  Professor  Wood- 
bridge,  of  the  Boston  Institute  of  Technology,  made  a 


Fig.  54. — Position  assumed  in  writing  with  the  desk  too  low. 


very  thorough  examination  into  the  hygienic  condition 
of  160  public-school  buildings  of  Philadelphia.  In  sum- 
ming up  the  result  of  their  investigation  they  say  that, 
next  to  uncleanliness,  the  greatest  evil  related  to  improper 
ventilation;  of  small  yards,  due  to  the  close  proximity 
of  buildings,  some  of  them  many  stories  in  height;  the 
presence  of  coal  gas;    lack  of  sunshine;    in  the  outside 


DEFECTS  IN  SCHOOL-BUILDINGS.  293 

air,  close  proximity  of  outhouses  improperly  constructed 
or  carelessly  cleaned  and  flushed  ;  the  keeping  of  wraps 
in  school-rooms  or  adjacent  unventilated  closets,  and 
the  almost  total  absence  of  ventilation  by  transoms, 
and  in  many  instances  the  use  of  storm  doors,  rendering 
ventilation  impossible  save  at  the  expense  of  the  chil- 
dren's health.  In  one  building,  accommodating  200 
children,  the  sun  never  entered,  save  in  one  room  at  the 
noon  intermission.  In  some  buildings  there  were  as  many 
as  nine  rooms  never  cheered  by  the  sun.  Fan  or  shaft 
ventilation  could  not  be  introduced  without  great  ex- 
pense, but  properly  arranged  door  and  window  transoms 
for  ventilation  could  be  placed  in  every  building  at  little 
cost,  thus  admitting  fresh  air  without  occasioning  draft. 
This  committee  recommended  that  every  building  should 
be  supplied  with  such  means  of  ventilation  as  will  insure 
free  circulation  of  air  throughout  the  building.  The 
prolific  cause  of  the  spread  of  contagious  diseases  is  the 
keeping  of  wraps  in  school-rooms.  The  committee 
found  that  at  least  three-quarters  of  the  older  buildings 
had  no  cloak-rooms,  or  very  inadequate  ones.  In  many 
cases  there  were  no  means  of  ventilating  such  rooms 
except  through  the  school-rooms. 

In  his  annual  report  for  the  year  1915  Dr.  Cornell/ 
Chief  of  the  Division  of  Medical  Inspection  of  Public 
Schools  of  Philadelphia,  states  that,  "Computation  of 
the  sanitary  grade  of  the  Philadelphia  School  plant, 
taken  as  a  whole,  and  using  the  system  devised  by  this 
division,  was  80.8  of  a  possible  perfect  100.  Our  new 
school  buildings  are  models  of  their  kind,  and  some  of 
the  school  districts,  notably  the  9th,  present  almost 
perfect  conditions.  The  old  school  plant  of  Philadelphia, 
however,  representing,  as  it  does,  the  architecture  of 
forty  years  ago,  is  badly  in  need  of  renovation.  The  7th 
school  district,  representing  an  old  portion  of  the  city, 
furnishes  the  most  marked  example  of  this  condition. 

It  is  a  well-known  fact  that  the  constant  breathing  of 

^  Annual  Report  of  the  Bureau  of  Health,  1915,  p.  210. 


294  SCHOOL  HYGIENE. 

air  markedly  vitiated  by  the  excretions  from  the  lungs  of 
other  persons  exerts  a  detrimental  influence  upon  the 
vital  powers  of  the  system.  Nevertheless  we  find  many 
of  our  public-school  buildings  overcrowded,  and  in  conse- 
quence the  way  is  opened  for  the  more  general  distribu- 
tion of  the  micro-organisms  of  disease  when  brought 
into  such  an  overcrowded  space. 

The  greater  prevalence  of  such  diseases  as  diphtheria, 
measles,  and  scarlatina  during  the  autumn  months  can 
be  definitely  traced  to  the  very  intimate  association  of 
children  in  overcrowded  and  poorly  ventilated  school- 
rooms, and  to  the  diminished  resistance  of  their  bodies 
to  infection  in  consequence  of  the  injurious  effects  of 
such  overcrowding. 

We  have  a  general  knowledge  of  the  overcrowded  con- 
dition of  the  public  schools  in  different  places,  but,  so 
far  as  I  know,  no  systematic  effort  has  been  made  to 
gather  detailed  information  regarding  the  ventilation 
of  the  public  schools,  except  that  published  by  the 
State  Board  of  Health  of  Ohio  (1901)  for  all  the  schools 
in  cities  and  towns  of  that  State.  This  report  is  most 
interesting  and  important,  and  should  be  duplicated 
elsewhere.  The  tables  given  in  this  report  show  the 
number  of  square  feet  of  floor  space  and  the  air  space 
for  each  pupil  in  a  room,  as  well  as  the  ratio  of  window 
area  to  floor  space.  The  investigation  shows  that  18 
per  cent,  of  the  schools  contain  one  or  more  rooms  that 
fall  below  the  minimum  standard  of  15  square  feet  of 
floor  space,  and  a  still  greater  number  (28  per  cent.)  fall 
below  the  minimum  standard  of  200  cubic  feet  of  air 
space,  while  75  per  cent,  of  the  school-buildings  have 
rooms  that  are  deficient  in  light  in  that  they  fall  below 
the  standard  of  a  window  area  of  20  per  cent,  of  that  of 
the  floor  space. 

Conditions  such  as  these  are,  no  doubt,  very  general 
throughout  the  country,  since  there  is  no  probability  that 
the  conditions  are  worse  in  Ohio  than  elsewhere.  With 
conditions  such  as  these  prevailing  in  our  public  schools 


MEDICAL  INSPECTION  OF  SCHOOLS.  295 

it  is  no  wonder  that  diseases  of  the  respiratory  tract  are 
so  readily  disseminated  among  school-children.  More- 
over, deficient  ventilation  and  lighting  are  potent  agen- 
cies in  undermining  the  vitality  of  the  bodies  of  growing 
children.  It  is  of  the  greatest  importance  that  the  chil- 
dren of  onr  public  schools  be  protected  from  all  detri- 
mental agencies  pos>ible. 

Medical  Inspection  of  Schools. — Medical  inspection 
of  schools  and  school  children  is  conducted  on  one  of 
two  principal  plans.  In  many  European  states  the  in- 
spection is  far-reaching  in  its  effects,  as  the  general  health 
and  development  of  the  child  are  considered.  Any  defects 
in  the  physical  condition  of  the  children  or  their  home 
and  school  surroundings  are  investigated  and  remedied. 
The  other  plan  of  school  inspection  is  directed  primarily 
toward  the  detection  of  infectious  diseases  among  the 
children  and  the  exclusion  of  sick  children  from  school 
until  they  are  well. 

In  some  of  the  countries  of  Europe  medical  inspection 
of  schools  has  been  developed  to  a  high  plane.  In 
Hungary,  for  instance,  the  position  of  school  physician 
is  an  established  one,  and  the  duties  of  this  officer  are 
well  defined.  It  is  the  duty  of  the  school  physician 
to  examine  and  study  the  school-buildings  from  a  sani- 
tary standpoint,  as  well  as  their  contents  and  surround- 
ings. It  is  his  duty  to  investigate  the  purity  of  the  air 
in  each  class-room,  and  analyze  it  systematically  from 
time  to  time.  He  must  inspect  the  lighting,  heating, 
and  ventilation  of  each  of  the  class-rooms,  and  regulate 
the  number  of  children  in  each  room.  On  the  basis  of 
yearly  measurement  and  examination  of  the  children,  he 
must  direct  the  proper  seating  of  each,  not  only  with  re- 
gard to  the  adaptability  of  the  form  and  size  of  the  desks 
to  the  age  of  the  pupils,  but  also  with  regard  to  special 
requirements  of  certain  pupils  on  account  of  defective 
eyesight  or  hearing.  He  is  also  required  to  analyze  the 
drinking-water  used  in  the  schools,  and  endeavor  to  pro- 
cure healthy  drinking-water.     When  disinfection  of  the 


296  SCHOOL  HYGIENE. 

school  becomes  necessary,  he  must  see  that  it  is  properly- 
carried  out. 

When  the  school  physician,  in  any  of  these  instances, 
notices  hygienic  defects,  he  must  inform  the  director  of 
the  institution,  and  make  suggestions  for  remedying  or 
removing  such  defects.  He  must  also  see  that  the  laws 
of  public  health  and  the  legislation  of  the  board  are 
carefully  carried  out. 

With  regard  to  the  health  of  the  pupils,  it  is  the  duty 
of  the  school  physician  to  examine  all  new  pupils  on 
entering  a  school.  These  examinations  are  to  be  of  such 
a  detailed  and  systematic  character  as  to  afford  a  knowl- 
edge of  the  health  of  each  child.  He  must  make  special 
observations  to  determine  the  extent  to  which  the  pupil 
may  safely  take  part  in  the  regular  gymnastic  exercises 
of  the  school,  or  whether  these  must  be  in  part  or 
entirely  prohibited.  He  must  examine  each  new  pupil 
to  determine  whether  it  is  suffering  from  any  infectious 
disease,  especially  tuberculosis.  He  must  also  examine 
the  spinai  column  to  determine  the  presence  of  curvature, 
in  order  that  special  gymnastic  exercises  may  be  pre- 
scribed to  overcome  this  defect.  He  must  examine  the 
eyes  and  ears,  and  determine  the  degree  of  vision  and  the 
hearing  power. 

These  systematic  examinations  of  the  pupils  are  re- 
peated during  the  school  year,  and  a  careful  record  must 
be  kept  of  the  progress  of  each  pupil  in  regard  to  the 
uniform  and  healthful  development  of  the  body. 

The  sanitary  inspection  of  schools  and  school-children 
has  been  very  generally  adopted  in  the  larger  cities  of 
the  United  States  during  the  last  decade.  Where  such  a 
system  is  adopted,  as  in  New  York,  Boston,  Chicago,  and 
Philadelphia,  a  corps  of  medical  inspectors  is  appointed, 
whose  duty  it  is  to  examine  all  children  whom  the 
teacher  believes  to  be  suffering  from  disease.  In  this 
manner  many  incipient  cases  of  infectious  disease  are 
detected  and  isolated  before  the  danger  of  dissemination 
is  very  great.     The  great  value  of  these  inspections  is 


MEDICAL  INSPECTION  OF  SCHOOLS.  297 

shown  in  a  report  made  by  Dr.  Cornell  in  his  annual 
report  of  the  work  of  the  Division  of  School  Inspection, 
Philadelphia  (Report  of  the  Bureau  of  Health,  19 15). 
It  gives  the  following  summary  of  the  physical  defects 
encountered  in  the  schools  during  the  year  ending 
Jime30,  1915: 

Eye 22,915 

Nose,  throat,  and  mouth 28,716 

Ear 1,858 

Teeth 75,309 

Orthopedic 4,519 

Nutrition 2,576 

Heart 852 

Nervous  system 641 

Defective  mentality 349 

Gastro-intestinal 30 

Skin 25,418 

Acute  ilhiess  and  accidents 2,946 

Not  vaccinated 663 

Miscellaneous 799 

Total 167,591 

The  conditions  most  frequently  encountered  in  school 
children,  and  which  were  recommended  for  treatment, 
were   the   following : 

Eye  strain 16,585 

Squint 1,406 

Conjunctivitis 1,886 

Stye 1,437 

Blepharitis 1,210 

Enlarged  tonsils 10,683 

Nasal  obstruction 10.012 

Nasal  catarrh 6,136 

Decayed  teeth  (i  to  3) 49,420 

Decayed  teeth  (more  than  3) 24,360 

Irregular  teeth 1,286 

Stoop  shoulders 4,201 

Dermatitic 3,i4S 

Eczema i,93i 

Offensive  and  unclean i,oiS 

Pediculosis io,S47 

Wounds 6,877 

Acute  illness 2,387 

In  addition  to  the  medical  inspectors,  a  number  of 
trained  nurses  are  also  employed  in  the  school  inspection 


298  SCHOOL  HYGIENE. 

work.  The  nurses  visit  the  homes  of  school  children 
where  their  instruction  may  prove  helpful,  and  in  addi- 
tion to  this  they  treat  cases  of  minor  contagious  diseases 
found  by  them  in  the  schools  or  sent  to  them  by  the 
school  inspector. 

The  medical  department  of  the  Philadelphia  High 
School  for  girls  was  established  in  1893.  Prior  to  this 
time  the  attendance  of  any  physician  was  depended  upon 
in  an  emergency,  so  that  much  time  was  lost,  and  the 
uncertainty  of  obtaining  assistance  was  great.  In  1893 
the  services  of  a  graduate  of  the  Woman's  Medical 
College  were  secured.  The  duties  of  the  head  of  the 
medical  department  constantly  increased  from  one  hour 
a  day  to  continual  attendance  from  the  opening  of  the 
school  at  9  A.  M.  until  the  close  of  the  session  at  2  p.  m. 

At  the  beginning  of  each  school  year  in  September  all 
vaccination  certificates  and  scars  are  examined ;  in  doubt- 
ful cases  a  certified  re-vaccination  is  required.  Teachers 
at  the  beginning  of  each  morning  session  inquire  whether 
any  student  is  suffering  from  sore  throat,  headache  or 
other  ailment;  all  such  are  at  once  referred  to  the  medical 
room.  A  daily  record  of  students  sent  to  the  medical 
room  is  carefully  kept.  Any  student  with  a  temperature 
of  100°  F.  is  detained  in  the  "sick-room  "  until  the  tem- 
perature becomes  normal.  If  a  rise  takes  place,  the 
student  is  sent  home  in  a  carriage.  On  stormy  days 
students  who  have  wet  shoes,  stockings,  or  skirts  are 
required  to  report  at  the  medical  room,  where  dry  gar- 
ments are  provided.  All  wet  clothing  is  dried  in  a  room 
prepared  for  the  purpose,  and  is  made  ready  for  the 
student  at  recess  in  the  medical  room  at  noon.  Every 
part  of  the  entire  building  is  thoroughly  cleansed  daily. 
The  balustrades  and  desks  throughout  are  carefully 
cleansed  each  day  with  antiseptic  solution.  The  drink- 
ing-water is  filtered,  then  sterilized,  and  the  ice  is  made 
from  sterile  water.  The  sanitary  condition  of  the  toilet- 
rooms  is  excellent.  There  are  now  individual  compart- 
ments, where  formerly  there  were  congregate  rooms. 


MEDICAL  INSPECTION  OF  SCHOOLS.  299 

The  objects  to  be  attained  in  the  systematic  daily  medi- 
cal inspection  of  schools  are  :  (i)  The  early  detection  of 
any  cases  of  communicable  diseases  among  the  children 
and  their  prompt  exclusion  from  the  school.  (2)  The 
discovery  of  children  suffering  from  non-communicable 
diseases  or  physical  defects  which  hinder  their  proper 
advancement  in  their  studies,  such  as  defective  vision 
and  hearing.  (3)  To  note  the  growth  and  development 
of  the  school-children.  Defects  in  development  and  im- 
perfect growth  should  be  noted  and  the  causes  underlying 
them  ascertained.  In  this  respect  the  intelligent  teacher 
can  be  of  great  assistance  to  the  medical  inspector  in 
pointing  out  the  defects  noted  through  the  more  intimate 
association  with  the  children.  Where  imperfect  develop- 
ment arises  from  lack  of  proper  or  sufficient  food  and 
clothing,  the  social  and  financial  condition  of  the  parents 
should  be  brought  to  the  attention  of  charitable  organi- 
zations for  investigation  and  amelioration. 

Control  of  Disease  in  New  York  Schools. — "The  modern 
conception  of  the  transmission  of  infectious  diseases  has 
led  to  certain  modifications  in  the  attitude  of  the  Depart- 
ment of  Health  in  regard  to  its  methods  of  dealing  with 
these  diseases  in  reference  to  the  school. 

"  Cases  of  scarlet  fever  are  excluded  from  school  for  at 
least  five  weeks,  or  until  desquamation  is  complete  and 
all  purulent  discharges  have  ceased.  If  quarantine  is  ob- 
served by  the  family,  children  and  others  who  have  had 
scarlet  fever  are  immediately  removed  to  another  address. 
They  may  return  to  school  at  the  end  of  five  days,  if,  in 
the  meantime,  tbey  do  not  develop  the  disease,  but  they 
must  present  a  special  school  certificate  issued  by  the  de- 
partment. If  they  continue  to  reside  at  home,  they  can- 
not return  to  school  until  the  case  of  scarlet  fever  has 
been  officially  discharged  by  the  Department  of  Health. 

"In  cases  of  measles,  the  patient  is  excluded  from 
school  until  five  days  after  the  appearance  of  the  rash,  at 
which  time,  if  he  is  otherwise  well  and  all  catarrhal  dis- 
charges have  ceased  and  the  cough  has  disappeared,  he 


300  SCHOOL  HYGIENE. 

may  return.  Children,  and  other  members  of  the  family 
who  have  had  the  disease,  may  continue  in  school,  pro- 
vided that  quarantine  at  home  is  properly  observed. 
Children,  or  other  members  of  the  family  who  have  not 
had  the  disease,  and  are  immediately  removed  to  another 
residence,  may  return  to  school  at  the  end  of  fourteen 
days,  the  usual  limit  of  the  period  of  incubation,  upon 
presentation  of  a  special  school  certificate  issued  by  the 
Department  of  Health  ;  if  continuing  to  reside  at  Jiome, 
they  must  not  be  re-admitted  until  the  case  has  been 
oflEicially  discharged  by  the  Department  of  Health. 

"  Children  suffering  from  German  measles  are  excluded 
for  one  week,  at  the  end  of  which  time  they  must  be  seen 
by  a  school  medical  inspector  and  will  be  re-admitted  on 
his  certificate.  Other  members  of  the  family  who  have 
not  had  the  disease  are  excluded  until  the  school  medical 
inspector  recommends  their  re-admission.  Children  in 
the  family  who  have  had  the  disease  may  remain  in 
school. 

"Children  suffering  from  chicken-pox  are  excluded 
from  school  until  all  scabs  have  disappeared,  at  which 
time  the  child  must  be  seen  by  a  school  medical  inspec- 
tor and  re-admitted  on  his  certificate.  All  other  children 
of  the  family  who  have  not  had  the  disease  are  excluded 
until  the  school  medical  inspector  recommends  their  re- 
admission.  Children  in  the  family  who  have  had  the 
disease  may  remain  in  school. 

"Children  suffering  from  whooping-cough  are  excluded 
from  school  until  the  whoop  has  entirely  disappeared, 
which,  generally  speaking,  means  from  six  weeks  to  two 
months.  In  public,  parochial,  and  all  other  free  schools, 
a  child  must  be  seen  by  the  school  medical  inspector  and 
be  re-admitted  upon  his  certificate.  In  private  schools, 
the  child  may  be  re-admitted  on  the  certificate  of  his  own 
physician.  In  either  case  the  child  must  be  again  ex- 
cluded if  the  characteristic  whoop  should  recur. 

"Children  suffering  from  mumps  are  excluded  until 
the  swelling  has  entirely  subsided.     In  public,  parochial^ 


MEDICAL  INSPECTION  OF  SCHOOLS.  301 

and  other  free  schools  the  child  must  be  seen  by  the 
school  medical  inspector  and  be  re-admitted  upon  his 
certificate.  In  private  schools,  the  child  may  be  re-ad- 
mitted on  the  certificate  of  its  own  physician.  All  chil- 
dren of  the  family  who  have  not  had  the  disease  are  ex- 
cluded until  the  school  medical  inspector  recommends 
re-admission.  Children  in  the  family  who  have  had  the 
disease  may  remain  in  school. 

"  Children  suffering  from  diphtheria  are  excluded  for  a 
minimum  period  of  one  week,  and  must  not  be  re-ad- 
mitted until  all  symptoms  have  disappeared  and  the  cul- 
ture is  negative.  A  certificate  from  the  Department  of 
Health  must  be  presented  upon  re-admittance.-  If  quar- 
antine is  observed,  children  and  others  who  have  been 
immunized  aeainst  the  disease  and  cultures  from  whose 
throats  do  not  show  diphtheria  bacilli  may  return  to 
school.  If  children  or  others  in  the  family  are  immedi- 
ately removed  to  another  address  and  cultures  taken  from 
nose  and  throat  is  negative,  they  may  be  re-admitted,  but 
must  present  a  special  school  certificate  issued  by  the  de- 
partment. If  continuing  to  reside  at  home  and  the  above 
precautions  are  not  taken,  they  cannot  be  re-admitted 
until  the  case  has  been  officially  discharged  by  the  De- 
partment of  Health. 

' '  When  a  teacher  is  a  member  of  a  family  or  house- 
hold in  which  a  contagious  disease  occurs  the  teacher 
must  be  excluded,  except  that  continuance  at  school  may 
be  permitted  at  the  discretion  of  the  department.  A 
special  certificate  must  be  issued  for  this  purpose."  ^ 

^  Monthly  Bulletin,  New  York  City  Department  of  Health,  August,  1913. 


CHAPTER     XIII. 
MILITARY    HYGIENE. 

The  health  and  efficiency  of  an  army  are  dependent 
upon  the  physical  condition  of  the  individual  soldier  and 
the  hygienic  condition  of  his  environment,  the  nature  of 
his  food-supply,  qualitatively  as  well  as  quantitatively; 
the  nature  of  his  clothing,  and  the  nature  and  extent  of 
his  physical  exercise. 

The  Recruit.— It  is  evident  that  the  health  and  effi- 
ciency of  an  army  rest  fundamentally  upon  the  physical 
condition  of  the  recruit,  and  consequently  great  care  is 
exercised  in  the  selection  of  individuals  for  enlistment. 
The  physical  condition  and  endurance  of  the  recruit  are 
influenced  directly  by  his  age,  height,  weight,  and  gen- 
eral physical  development. 

The  age  of  the  recruit  has  an  important  influence  upon 
his  physical  endurance  and  adaptability  to  the  service. 
In  men  of  eighteen  to  twenty  years  of  age  the  ossifica- 
tion of  the  bones  and  the  general  muscular  develop- 
ment are  as  yet  incomplete,  and  therefore  they  are  more 
liable  to  succumb  to  the  strenuous  duties  of  the  soldier. 
In  like  manner,  men  over  forty-five  years  of  age  fre- 
quently lack  endurance  because  of  beginning  degenera- 
tive changes  in  the  circulatory  organs.  It  has  been  found 
that  the  most  inefficient  armies  were  those  in  which  the 
largest  proportion  of  the  men  were  below  twenty-two 
years  of  age,  though  it  has  also  been  found  that  young 
men  are  most  easily  trained  and  are  more  likely  to  follow 
orders  without  question.  The  age-limit,  except  in  cases 
of  re-enlistment,  should,  therefore,  be  from  twenty-one 
to  thirty-five  years. 

In  peace  the  maximum  age  for  cavalry  is  thirty  years, 

302 


THE  RECRUIT. 


303 


for  all  other  arms,  thirty-five  years;  the  minimum  for 
musicians,  sixteen  years,  for  all  others,  eighteen  years. 
Volunteers  are  accepted  between  eighteen  and  forty-five, 
but  men  were  drafted  in  the  Civil  War  only  between 
twenty  and  forty-five  years.  The  unorganized  militia 
are  between  eighteen  and  forty-five  years^  In  the  Eng- 
lish army,  according  to  Parke,  men  are  enlisted  from 
eighteen  to  twenty-five  years  of  age. 

The  relative  proportions  of  height,  weight,  and  chest 
measurement  of  the  recruit  are  valuable  indicators  of  his 
general  physical  development,  and,  therefore,  of  his 
adaptability  for  the  service. 

The  following  table  ^  shows  the  relative  proportions 
of  height,  weight,  and  chest  measurement  as  found  in 
averaofe  men: 


Chest  Measurement. 

Height. 

Weigtit. 

At  E.xpiration. 

Mobility. 

Feet. 

Inches. 

Cm. 

Pounds. 

Kg. 

Inches.      Cm. 

Inches.     Cm. 

Sr^j 

64 

162.5 

128 

57-9 

32           81.2 

2              5.0 

5A 

65 

165. 1 

130 

58.8 

32           83.8 

2              5.0 

5A 

66 

167.6 

132 

59-7 

32*         85.0 

2              5.0 

5A 

67 

1 70. 1 

134 

60.7 

33         86.3 

2               5.0 

5t*^ 

68 

172.7 

141 

63.8 

1>Z\      86.9 

2\           6.3 

5A 

69 

175.2 

148 

67.0 

33*       87.6 

2i            6.3 

s\% 

70 

177.8 

155 

70.2 

34        S8.9 

2l            6.3 

s\\ 

71 

180.3 

162 

73-3 

34i      89.5 

2I             6.3 

6 

72 

182.8 

169 

76.5 

34f      90.8 

3"        8.8 

(^-h 

73 

185.4 

176 

79-7 

35i      92.0 

3          8.8 

It  is,  however,  the  manual  states,  not  necessary  for  the 
recruit  to  conform  exactly  to  the  figures  in  the  table.  A 
variation  of  10  pounds  (4.5  kg.)  in  weight  or  2  inches 
(5  cm.)  in  chest  measurement  (at  expiration)  below  the 
standard  given  in  the  table  is  admissible,  provided  the 
applicant  is  otherwise  vigorous  and  healthy. 

The  Surgeon-General  gives  the  following  directions 
for  the  examination  of  recruits: 

"  The  minimum  height  of  a  recruit  is  at  present  fixed 
at  5  feet  4  inches  for  all  branches  of  the  ser\'ice,  although 

^  Manual  of  the  Medical  Department  of  the  Army,  edition  of  1900,  p.  loi. 


304  MILITARY  HYGIENE. 

recruiting  officers  are  allowed  to  exercise  their  discretion 
as  to  the  enlistment  of  desirable  recruits  (such  as  band 
musicians,  school-teachers,  tailors,  etc.)  who  may  fall  not 
more  than  \  inch  below  the  minimum  standard  of  height; 
the  maximum  height  for  the  calvary  service  is  5  feet  10 
inches;  that  for  infantry  and  artillery  is  governed  by  the 
maximum  weight,  to  which  should  be  applied  the  rule 
for  proportion  in  height. 

"The  minimum  weight  for  all  recruits  is  125  pounds, 
except  for  the  cavalry,  in  which  enlistment  may  be  made 
without  regard  to  a  minimum  weight  provided  the  chest 
measurement  and  chest  mobility  are  satisfactory.  The 
maximum  for  infantry  and  artillery  is  190  pounds;  for 
cavalry  and  light  artillery,  165  pounds. 

"The  chest  mobility — i.  (?.,  the  difference  between  the 
measurement  at  inspiration  and  expiration — should  be  at 
least  2  inches  in  men  below  5  feet  7  inches  in  height,  and 
2\  in  those  above  that  height." 

The  height  of  recruits  must  be  at  least  165  centimeters; 
minimum  chest  measurement,  75  centimeters,  with  at 
least  5  centimeters  expansion;  and  the  weight  54  to  81 
kilograms.  In  the  cavalry  service  the  maximum  weight 
is  75  kilograms. 

According  to  Parke,  probably  63  inches  at  nineteen 
years  of  age,  and  120  pounds  weight,  should  be  the 
minimum  height  and  weight  according  to  age,  even  in 
times  of  greatest  pressure. 

In  France  the  weight  is  reckoned  at  the  rate  of  700  to 
725  grams  for  each  centimeter  of  chest  circumference. 

Any  defect  or  deformity  which  is  likely  to  interfere 
with  the  duties  of  a  soldier  will  cause  the  rejection  of  the 
applicant.  He  must  have  free  use  of  his  limbs  and  be 
active  and  vigorous.  The  character  of  the  feet  and  legs 
is  a  most  important  matter  for  investigation  by  the  re- 
cruiting officer  because  of  the  nature  of  the  service  in 
which  the  soldier  engages.  Any  defects  or  imperfect 
development  of  the  feet  and  legs  will  probably  be  detected 
by  the  examining  officer  from  the  exercise  in  walking, 


TRAINING  OF  THE  RECRUIT.  305 

running,  and  jumping  to  which  the  applicant  is  subjected. 
The  hearing  must  be  normal  and  the  vision  without 
evident  defect.  The  recruit  must  be  "effective,  able- 
bodied,  sober,  free  from  disease,  and  of  good  character 
and  habits."  The  mere  fact  that  the  recruit  presents 
himself  for  examination  in  ragged  or  filthy  clothes,  or  is 
filthy  in  his  person,  is  sufficient  to  cause  his  rejection. 
The  most  frequent  cause  of  rejection  of  applicants  is 
some  form  of  defective  development.  For  the  year  1899 
there  were  examined  70,311  men  for  enlistment  in  the 
regular  army,  of  whom  47,899  were  accepted,  or  681.24 
out  of  every  1000  examined.  "  Of  every  1000  examined, 
74.56  were  rejected  on  account  of  imperfect  physique, 
including  overheight,  underheight,  overweight,  and  un- 
derweight; 41.43  for  diseases  of  the  eye,  38.06  for  diseases 
of  the  circulator}^  system,  26.53  for  diseases  of  the  diges- 
tive system,  22.43  ^^^  affections  of  the  genito-urinary 
system,  17  for  venereal  diseases,  9.61  for  hernia;  while 
9.81  were  rejected  as  generally  unfit  or  undesirable,  3.74 
as  minors,  3.12  on  account  of  bad  or  doubtful  character, 
and  only  1.32  on  account  of  illiteracy,  imperfect  knowl- 
edge of  the  English  language,  or  mental  insufficiency."  ^ 

Training  of  the  Recruit. — Physical  Training. — In 
order  to  increase  his  endurance,  as  well  as  add  to  his 
general  usefulness  as  a  soldier,  the  recruit  must  be  sub- 
jected to  thorough  physical  training  as  well  as  training 
in  the  art  of  war  before  eno^as:inof  in  active  warfare. 
Physical  training,  if  conducted  systematically,  will  greatly 
increase  the  endurance  of  the  raw  recruit.  Without  this 
preliminary  training  most  men,  however  well  propor- 
tioned they  may  be,  will  succumb  to  the  arduous  duties 
of  active  warfare. 

The  recruit  should  be  instructed  in  swimming,  not 
only  because  it  is  a  most  useful  physical  training,  but 
also  because  it  is  an  acquirement  that  may  be  of  the 
greatest  service  in  his  calling.  Dancing,  fencing,  and 
general  gymnastic  exercises  are  of  great  value  in  training 

^  Report  of  the  Surgeon- General,  p.  27,  1900. 
20 


3o6  MILITARY  HYGIENE. 

the  coordinate  movement  of  muscles,  as  well  as  in  aiding 
in  the  uniform  development  of  the  body  and  in  increasing 
the  general  physical  endurance.  Exercises  in  singing 
are  valuable  in  improving  the  lungs  and  in  developing 
the  breathing  capacity.  Any  exercise  that  aids  in  im- 
proving the  general  physical  condition  of  the  body  should 
be  made  use  of  in  the  preliminary  training  of  the  recruit. 

Moral  Training. — The  great  danger  from  vice  in  the 
army  arises  principally  from  the  fact  that  large  num- 
bers of  men  are  brought  together,  and  are,  in  times  of 
peace,  compelled  to  spend  a  portion  of  their  time  in  com- 
parative idleness.  The  utilization  of  definite  portions 
of  each  day  in  perfecting  the  men  in  their  knowledge 
of  the  military  art  will,  in  large  part,  prevent  vice,  and 
gives  at  the  same  time  healthful  occupation  to  the  mind, 
thus  preventing  home-sickness.  The  soldier  should  also 
be  instructed  in  other  lines  of  useful  knowledge,  such  as 
cooking,  washing,  and  sewing,  so  that  he  may  contribute 
toward  the  general  comfort  of  the  army  as  well  as  his 
own  welfare. 

The  influence  of  the  canteen  law  has  given  rise  to  a 
great  deal  of  discussion  recently.  There  are  two  sides  to 
this  question,  each  having  its  earnest  advocates,  and  it  is 
evident  that  the  solution  of  the  problem  should  be  left  to 
the  efficient  heads  of  the  army.  They  have  opportunities 
for  the  formation  of  unbiased  judgment  which  are  denied 
to  those  on  the  outside.  A  priori^  the  entire  exclusion 
of  alcoholic  beverages  would  be  preferable,  by  far,  if  it 
could  be  accomplished. 

The  Association  of  Military  Surgeons,  in  its  annual 
convention  at  St.  Paul,  May,  1901,  unanimously  adopted 
a  resolution  declaring  that  the  abolition  of  the  canteen 
had  resulted  in  an  increase  of  "  intemperance,  insubor- 
dination, discontent,  desertion,  and  disease,"  at  the  vari- 
ous army  posts,  and  urging  that  it  should  be  re-established 
at  the  earliest  possible  date,  "in  the  interests  of  discipline, 
morality,  and  sanitation." 

Food  of  the  Soldier. — Under  present  laws  and  regu- 


FOOD  OF  THE  SOLDIER.  307 

lations  the  soldier  may  have  any  variation  of  his  diet 
within  certain  money  value  limits  which  his  officers  con- 
sider necessary  for  his  well-being.  His  ration  is  fixed  by 
law,  but  his  diet  depends  on  the  intelligent  supervision 
of  company  officers  and  the  ability  of  company  cooks. 
Major  Howard  ^  states  that  ' '  the  diet  of  the  soldier  is 
what  the  company  commander  and  his  first  sergeant  and 
cook  may  choose  to  make  it,  the  materials  being  amply 
provided  by  the  official  ration." 

The  soldier's  ration  consists  of  the  following  :  342 
grams  of  pork  or  bacon,  or  567  of  fresh  beef ;  454  of  hard 
bread,  or  566  of  flour  ;  68  of  beans  or  peas,  or  45  of  rice 
or  hominy  ;  45  of  green  coffee  ;  17  of  salt  ;  68  of  sugar; 
besides  pepper,  vinegar,  and,  at  times,  tea  instead  of 
coffee. 

The  food  should  be  thoroughly  cooked,  and  free  from 
fermentative  or  putrefactive  changes.  Ripe  fruit  may 
be  eaten  in  moderation,  but  green  or  over-ripe  fruit 
should  be  avoided,  because  these  give  rise  to  disturbances 
of  the  digestive  organs. 

With  such  ample  provision  of  materials  it  has  generally 
been  found  possible  to  adapt  the  diet  to  any  climatic  con- 
ditions to  which  our  army  has  been  subjected  in  the  past 
few  years.  No  doubt  some  difficulty  was  experienced  in 
supplying  the  full  complement  of  fresh  meat  and  vege- 
tables in  the  tropics  at  all  times,  on  account  of  the  great 
distance  from  the  base  of  supplies,  but,  in  general,  there 
appears  to  have  been  little  real  inconvenience. 

There  has  been  considerable  discussion  as  to  the  suit- 
ability of  the  ration  to  tropical  conditions,  some  claiming 
that  an  excess  of  fat  and  a  deficiency  of  carbohydrates 
in  the  form  of  fresh  vegetables  and  fruit  was  supplied. 
There  is,  however,  provision  in  the  law  allowing  com- 
mutation of  the  rations,  thus  permitting  the  purchase  of 
food  in  the  local  markets,  and  in  this  manner  any  defects 
in  the  materials  supplied  can  be  remedied  to  advantage. 

Unless   the   duties  of  the  soldier  in    the   tropics   are 

^  Surgeon-  Gene raP s  Report,  p.  174,  1900. 


3o8  MILITARY  HYGIENE. 

arduous,  thus  necessitating  a  diet  rich  in  proteids,  the 
use  of  a  greater  proportion  of  vegetables  and  ripe  fruit 
than  is  the  custom  in  colder  climates  would  serve  to  re- 
duce the  danger  from  disordered  gastro-intestinal  function 
in  large  part.  Along  with  the  use  of  pure  water  such  a 
diet  should  serve  to  lessen  the  suffering  from  diarrhea 
and  dysentery. 

New  Ration  for  Soldiers. — Since  the  unpleasant  results 
during  the  Spanish  war  from  the  use  of  canned  beef  in 
the  tropics  the  Government  has  substituted  fresh  meats 
for  the  troops  in  the  Philippines.  At  considerably  greater 
expense  the  Government  has  bought  refrigerated  beef 
in  Australia  for  the  army  in  the  Philippines,  but  it  is 
only  available  for  troops  stationed  at  seaports  or  within 
easy  reach  inland.  It  will  keep  twenty  days  in  good 
condition  for  use,  but  it  is  not  an  ideal  meat  ration  for 
active  field  service  where  troops  are  on  the  march.  The 
most  practical  method  of  maintaining  a  meat-supply  for 
moving  troops  has  been  to  drive  cattle  along  with  the 
marching  column. 

The  trial  of  a  new  ration  called  "  roast-beef  hash " 
seems  now  likely  to  solve  some  of  the  problems  of  sub- 
sistence for  men  in  the  field.  This  is  a  canned  beef  that 
has  been  thoroughly  cooked  and  mixed  with  chopped 
and  cooked  potatoes  and  onions.  It  will  keep  indefinitely 
and  is  said  to  be  most  appetizing.  The  men  like  it,  and 
the  first  trial  has  proved  so  successful  that  a  larger  amount 
will  be  shipped.  It  is  packed  in  boxes  and  can  be  trans- 
ported readily  and  served  out  to  each  mess  quickly,  sup- 
plying on  occasion  a  complete  meal  ready  cooked.  On 
forced  marches  or  in  a  country  where  a  fire  is  not  desir- 
able it  is  a  very  convenient  food.  It  is  adapted  to  rapid 
marching,  where  it  is  impracticable  to  take  along  a 
supply  train,  pack  animals  being  able  to  carry  a  con- 
siderable amount,  and  in  case  of  necessity  each  man  can 
put  a  day's  supply  in  his  haversack. 

Clothing-  of  the  Soldier. — The  clothing  of  the  soldier 
requires  intelligent  supervision  in  order  to  adapt  it  to  the 


CLOTHING  OF  THE  SOLDIER.  309 

climate  of  tlie  locality  in  which  he  is  serving  as  well  as 
to  seasonal  variations. 

Underclothing — Light  woollen  underclothing  should  be 
supplied,  because  it  takes  up  moisture  from  the  skin  very 
readily,  and  thus  protects  against  chill  after  exercise.  In 
the  tropics  coarse  mesh  linen  underclothing  is  preferable, 
because  it  does  not  retain  the  moisture  as  does  woollen 
underclothing.  The  stockings,  on  the  other  hand,  should 
be  composed  of  about  equal  parts  of  cotton  and  wool. 
Woollen  stockings  are  apt  to  cause  sweating  of  the  feet, 
and  thus  induce  a  tender  condition  of  the  feet  which  is 
likely  to  produce  discomfort  or  even  suffering.  Cotton 
stockings  are  apt  to  be  cold,  and  are  therefore  not  suited 
for  colder  climates.  Olive-drab  woolen  shirts  should 
be  supplied  except  for  service  in  the  tropics,  where  a 
cotton  shirt  may  be  substituted. 

Outer  Garments. — The  uniform  should  be  adapted  to 
the  occupation  and  to  the  climate.  In  colder  climates 
woollen  garments  should  be  supplied,  the  weight  of  the 
goods  being  regulated  according  to  the  locality.  In  the 
tropics,  and  during  summer  in  the  temperate  zone,  the 
garments  should  be  made  of  materials  which  allow  of  the 
free  circulation  of  air.  The  oUve-drab  woolen  cloth  now 
generally  in  use  for  the  uniform  supplied  to  troops  in 
the  tropics  has  proved  quite  satisfactory. 

The  color  of  the  soldier's  uniform  is  of  an  olive-drab 
shade.  The  winter  imiform  is  woolen  cloth  and  the 
summer  uniform  of  cotton.  The  headdress  conforms 
in  color  to  that  of  the  uniform. 

The  color  of  the  uniform  is  of  great  importance  not 
only  on  account  of  its  heat-absorbing  powers  and  the 
facihty  with  which  it  allows  the  heat  of  the  body  to  pass 
off,  but  Hkewise  because  of  the  extent  to  which  it  ren- 
ders the  soldier  visible  at  a  distance.  Red  is  the  most 
conspicuous  color,  white  is  next  in  order,  while  gray  is 
least  conspicuous.  The  olive-drab  woolen  uniforms 
are  very  well  adapted  from  this  standpoint.  This  is  a 
point  that  should  be  considered  by  the  State  in  order  to 


3  lo  MILITAR  Y  HYGIENE. 

conserve  the  life  and  safety  of  its  soldiers.  During  the 
conflict  in  vSouth  Africa  the  British  officers  are  reported 
to  have  suffered  disproportionately  on  account  of  the 
color  of  their  uniforms. 

The  head-covering  is  of  great  importance,  especially 
in  the  tropics,  where  the  head  and  face  should  be  shaded 
from  the  fierce  rays  of  the  sun  and  against  rain.  The 
hat  worn  by  the  troops  in  the  tropics  meets  these  points 
fairly  well.  It  is  light,  and  allows  free  circulation  of  air, 
thus  limiting  the  danger  from  sunstroke. 

The  shoes  should  be  adapted,  as  near  as  may  be,  to  the 
feet  of  the  individual  wearing  them.  In  order  to  be  able 
to  meet  this  demand  satisfactorily,  the  State  should  sup- 
ply the  common  sizes  and  shapes  of  sole,  and,  besides 
this,  make  to  order  the  shoes  of  those  that  cannot  be 
fitted  properly  from  stock.  A  great  deal  of  discomfort 
and  suffering  may  be  avoided  by  such  a  course,  besides 
enhancing  the  endurance  and  efficiency  of  the  soldier. 

While  on  the  march  each  soldier  carries  also  his  blanket 
and  waterproof,  and  in  cold  climates  his  overcoat.  These 
articles  of  clothing  are  made  up  into  a  roll,  together  with 
the  toilet  articles,  and  this  is  slung  over  the  shoulder.  It 
is  not  likely  that  the  knapsack  formerly  in  use  will  again 
find  favor.  It  gave  rise  to  discomfort,  and  at  times  proved 
positively  injurious  because  it  had  to  be  buckled  on  firmly 
and  therefore  impeded  the  free  movements  of  the  soldier's 
arms  and  chest. 

When  the  soldier's  clothing  or  bedding  becomes  damp 
from  exposure  to  rain  or  heavy  dews,  it  should  be  dried 
in  the  sun  or  by  fires  at  the  first  opportunity  that  pre- 
sents itself. 

The  following  is  Major  Meacham's  opinion  v/ith  regard 
to  the  soldier's  clothing  for  field-service  in  the  tropics, 
based  upon  his  experience  in  northern  Luzon,  P.  I.  : 

' '  The  clothes  must  be  loose  and  comfortable.  On  the 
march,  part  woollen  should  be  worn  next  the  body.  Ex- 
perience during  the  past  wet  and  dry  seasons  shows  that 
the  clothing  now  furnished  is  fairly  well  adapted  to  this 
climate.      The  supply  at  the  depots  has  been  sufficient. 


CLOTHING  OF  THE  SOLDIER.  311 

The  shoes  and  socks  give  entire  satisfaction.  For  the 
march  the  Hght  woollen  sock  is  preferable. 

"The  recent  issue  of  campaign  hat,  with  corrugated 
sweat-bands  and  ventilation  in  the  sides,  possesses  ad- 
vantages not  obtainable  in  other  forms  of  headgear  for 
constant  use  and  all-around  field-service.  It  is  far  superior 
to  the  straw  hat,  and,  during  the  rainy  season,  to  any 
cork  or  pith  helmet.  The  latter  requires  more  or  less 
care  at  all  times,  both  on  and  off  the  head. 

"A  part  woollen  undershirt  is  necessary  to  protect  the 
body  from  sudden  chilling.  The  cotton  or  nankeen  under- 
shirt is  cold,  clammy,  and  sticks  to  the  body  while  in 
profuse  perspiration.  This  is  especially  noticeable  during 
the  five  minutes'  rest  given  hourly  on  a  regular  march. 

"The  lighter  issue  of  the  blue  flannel  shirt  answers 
fairly  well  at  all  times,  but  is  objectionable  in  some  re- 
spects. Its  color  more  rapidly  absorbs  the  heat,  and  can 
be  distinguished  a  long  distance,  making  the  wearer  a 
good  mark  for  the  enemy.  A  gray  flannel  shirt  of  medium 
weight  is  preferable.  The  flannel  shirt  has  the  advantage 
of  keeping  the  body  warm,  even  when  wet,  night  and  day. 
The  soldier  prefers  to  wear  the  blue  flannel  shirt  on  the 
march,  with  no  undershirt,  the  sleeves  rolled  up,  open  in 
front,  and  the  collar  well  rolled  back.  It  is  thus  made 
very  comfortable,  the  campaigner  readily  becoming  ac- 
customed to  the  sun's  rays.  One  great  objection  to  this 
shirt  is  its  irritating  effect  on  the  skin.  On  returning  to 
camp  at  night  the  soldier  puts  on  the  cotton  undershirt 
as  a  protection  against  this  irritation. 

"Of  the  clothing  furnished  at  present  for  active  cam- 
paigning I  have  found  that  the  light-gray  woollen  under- 
shirt of  light  weight,  with  an  overshirt  of  chambray  or 
gingham,  gives  comfort  and  satisfaction.  Personally  I 
have  found  the  most  comfort  from  the  gray  outing  flannel 
of  medium  weight,  worn  with  no  undershirt.  This  same 
material  of  a  khaki  color  would  be  still  better.  It  pre- 
vents chilling  ;  is  never  too  warm,  nor  sticks  to  the  body, 
but  absorbs  the  perspiration  and  dries  readily.  A  cotton 
undershirt  worn  under  this  while  in  camp  gives  one  the 


312  MILITARY  HYGIENE. 

greatest  amount  of  comfort,  and  is  sufficiently  warm  for 
the  night.  As  the  nights  here  are  usually  cool,  sufiticient 
covering  for  the  abdomen  must  be  worn.     For  this  the 

blue  flannel  shirt  answers  well;  in  fact,  it  has  become 
quite  customary  when  not  on  the  march,  but  lying  in 
camp,  for  the  soldiers  to  wear  the  blue  flannel  shirt  at 
night.  The  coolness  of  the  night  while  lying  down  is 
severely  felt  upon  the  abdomen  often  enough  to  keep  one 
awake  and  interrupt  his  rest.  Even  a  slight  covering  is 
a  help,  and  for  this  the  flannel  belly-band  is  worn.  The 
neglect  of  this  is  undoubtedly  the  predisposing,  if  not  the 
actual  exciting  cause  of  many  of  our  intestinal  ailments. 

"  The  white  jean  drawers  answer  all  conditions  at  all 
times;  they  are  loose,  comfortable,  and  safe. 

"  The  khaki  fatigue  uniforms  are  excellent. 

"During  the  wet  season  the  large  pouches  now  fur- 
nished are  of  more  service  than  the  rain  coat  or  mackin- 
tosh. They  protect  sufficiently  well  and  are  not  as  hot 
as  the  mackintosh;  besides  they  serve  as  a  blanket  or 
covering  at  night." 

Camps. — Tents. — The  tents  used  in  the  army  are  the 
hospital  tent,  the  officers'  wall  tent,  the  A-tent,  and  the 
shelter  tent,  which  is  a  modification  of  the  last.  Sol- 
diers give  the  preference  to  the  shelter  tent,  which  is 
light,  each  man's  piece  weighing  only  1.18  kilograms. 
Two  pieces  being  joined  together  by  buttons  and  button- 
holes, and  thrown  over  a  ridge  pole  supported  by  four 
uprights,  and  the  four  corners  fastened  to  pegs  driven  into 
the  ground,  form  a  tent  1.2  meters  high,  1.65  meters 
long,  and  having  a  spread  at  the  base  of  between  t.8  and 
2. 1  meters.  Such  a  tent  will  form  a  comfortable  shelter 
for  two  men,  unless  there  should  be  strong  winds  or 
driving  rains,  when  the  ends  should  be  closed  by  blankets 
or  an  extra  piece  of  shelter  tent.  The  uprights  and 
ridge  are  steadied  by  short  guy  ropes,  one  of  which  is 
furnished  with  each  piece  of  tent. 

Location  of  the  Camp. —  The  camp  should  not  be 
located  on  a  spot  that  has  recently  been  used  for  the 
same    purpose.       Camp  sites  should    also    be  frequently 


CAMPS.  313 

changed,  in  order  to  avoid  the  effects  of  soil  pollution 
which  might  result  from  long-continued  occupation.. 
The  camp  site  should  be  selected  with  reference  to  sev- 
eral important  particulars.  The  soil  of  the  locality 
should  be  dry,  sandy  in  character,  and  well  drained.  The 
site  should  also  be  so  located  as  to  afford  a  plentiful  sup- 
ply of  pure  and  wholesome  water.  Too  much  stress 
cannot  be  laid  upon  this  point.  Low-lying,  damp,  or 
marshy  localities  should  be  avoided  for  obvious  reasons. 

The  camp  should  be  laid  out  in  regular  order  with 
streets,  so  as  to  provide  ways  of  passing  freely  through 
the  camp.  The  camp  should  be  as  compact  as  will  be 
permissible  with  health  and  cleanliness. 

A  trench,  at  least  10  centimeters  in  depth,  should  be 
dug  around  each  tent,  so  as  to  exclude  surface  water,  and 
this  should  lead,  with  the  trenches  from  the  other  tents, 
into  a  larger  one  for  each  street,  so  as  to  conduct  the 
rain-water  from  the  camp-ground. 

Sanitary  Policing  of  the  Camp. — Frequently  this  mat- 
ter is  left  to  hired  civilians,  though  not  always.  The  camp 
streets  should  be  cleaned  regularly  every  day  and  all 
rubbish  burned  as  promptly  as  possible.  All  kitchen 
refuse  should  be  collected  twice  a  day  and  removed  from 
the  camp-grounds  or  buried  in  trenches  dug  for  the  pur- 
pose. The  tents  should  be  aired  each  day  by  opening 
the  doors  and  raising  the  walls  after  the  men  have  left 
them  in  the  morning.  All  bedding  should  likewise  be 
exposed  to  the  air  every  day  unless  the  weather  is  such  as 
to  prevent  it. 

Water-supply. — There  should  be  an  abundant  supply 
of  pure  water  for  all  purposes  for  which  it  is  needed. 
Where  the  wholesomeness  of  the  water  is  doubtful,  some 
method  of  purification  should  be  provided.  For  this  pur- 
pose the  Forbes  portable  water  sterilizer  (Fig.  55)  is  now 
frequently  employed. 

This  apparatus  is  in  very  common  use  in  the  various 
army  camps  in  the  tropics,  and  the  universal  report  is 
most  favorable  as  to  its  efficiency  in  preventing  the 
development    of    typhoid    fever   and    diarrheal   diseases 


314  MILITAR  Y  HYGIENE. 

among  the  troops.  Even  in  localities  where  typhoid 
fever  prevailed  the  introduction  of  the  apparatus  and 
the  exclusive  use  of  boiled  or  sterilized  water  arrested 
the  outbreak. 


Fig.  55. —  Furbes'  portable  water  sterilizer,  army  type. 

A  board  of  army  surgeons,  consisting  of  Majors  Reed, 
Shakespeare,  and  Vaughn,  appointed  for  the  purpose  of 
testing  various  types  of  apparatus  submitted  to  the  war 
department  for  use  in  sterilizing  water  in  the  field,  report 
that  "all  living  micro-organisms,  except  a  few  spore- 
bearing  bacteria,  are  destroyed  by  the  degree  of  heat 
attained  during  the  passage  of  the  water  through  the 
apparatus .  The  di  sad  vantage  of  the  escape  of  a  few  spore- 
forming  bacteria  through  this  apparatus  is  considered  to 
be  of  no  practical  importance  by  the  Board."   They  also 


BARRACKS.  3^5 

found  that ' '  there  is  no  loss  of  the  natural  gases  during 
the  passage  of  the  water  through  the  apparatus." 

The  treatment  of  water  with  disinfectants  has  received 
considerable  study,  and  the  hypochlorites  have  been 
found  valuable  for  this  purpose.  Sodium  peroxide  has 
also  been  tried  and  found  to  yield  a  safe  water. 

Provision  should  be  made  of  ample  opportunities  for 
bathing.  In  the  absence  of  large  bodies  of  water  in  the 
vicinity  of  the  camp  permitting  the  soldiers  to  engage  in 
swimming,  shower-baths,  at  least,  should  be  supplied  at 
convenient  points  on  the  camping-ground. 

Latrines. — The  latrines  should  be  situated  from  140  to 
150  meters  to  the  leeward  of  the  camp.  A  deep  and  nar- 
row trench  should  be  dug  for  the  purpose.  It  must  not 
be  too  wide,  or  it  will  require  more  earth  to  cover  the 
excreta.  Ki  least  three  times  each  day  the  excreta  should 
be  covered  with  earth  to  a  depth  of  2  to  3  decimeters,  or 
with  slaked  lime.  The  dry  earth  readily  absorbs  the 
putrifying  material  and  thus  rend-ers  it  inoffensive.  The 
bacteria  in  the  soil  destroy  the  organic  matter  contained 
in  the  excreta,  thus  rendering  them  harmless.  This  pro- 
cedure will  protect  the  excreta  from  flies  and  insects,  and 
limit  one  source  of  danger  of  general  infection  should 
there  be  unrecognized  cases  of  typhoid  fever  in  the  camp. 
The  excreta  of  all  cases  of  typhoid  fever  and  dysentery 
should  be  disinfected  at  once.  They  should  never  be 
thrown  into  the  trenches  without  this  precaution.  The 
excreta  in  the  trench  may  also  be  burned  daily  by  pour- 
ing kerosene  upon  them  and  applying  the  torch.  In  the 
tropics,  during  the  rainy  season,  the  dry-earth  closet  is 
being  used  for  hospitals  and  camps  in  towns.  The  excreta 
are  collected  in  galvanized  vessels,  covered  with  dry 
earth,  and  emptied  at  frequent  intervals.  New  sinks 
should  be  dug  when  the  old  ones  are  filled  to  within  6 
decimeters  of  the  top,  the  old  sinks  being  completely 
filled  with  earth. 

Barracks. — Besides  healthful  sites,  the  essential  con- 
ditions of  barracks  are  dryness,  warmth,  light,  amount 
of  floor  space,  and  air-supply. 


3i6 


MILITARY  HYGIENE. 


In  the  squad-room  each  man  should  have  at  least  30 
cubic  meters  of  air  space  and  465  square  decimeters  of 
floor  space,  and  south  of  36  degrees  north  latitude  the 
proportions  should  be  40  and  665,  respectively. 

There  should  be  more  space  allowed  if  the  barracks  are 
constantly  occupied,  because  the  dimensions  given  are 


Fig.  56. — Diagram  illustrating  ridge  ventilation. 

too  low  for  constant  occupation  during  active  exercise. 
The  official  recommendations  for  English  troops  in  India 
range  from  75  to  150  cubic  meters  of  air  space,  and  from 
620  to  1240  square  decimeters  of  floor  space. 

The  squad  room  should  be  not  less  than  35  decimeters 
nor  more  than  42.5  decimeters  in  height,  and  preferably 
about  70  decimeters  wide.  Excessive  height  and  width 
should  be  avoided  because  of  greater  difficulty  in  efficient 
ventilation. 

Ridge  ventilation  is  perfectly  satisfactory  for  barracks, 
or  it  may  be  accomplished  by  means  of  double  inlet  and 
outlet  tubes  in  the  roof  (see  Fig.  56),  so  constructed  that 
the  fresh  air  enters  through  the  outer  tube  and  the 
vitiated  air  takes  its  exit  through  the  inner  tube. 

There  should  be  ample  provision  for  bathing,  and  the 
water  supplied  as  pure  as  can  be  obtained.  If  its  purity 
is  open  to  question,  it  should  be  purified  by  sterilization, 
boiling,  or  filtration. 


MARCHES.  317 

The  latrines  require  careful  attention.    If  it  is  possible 

to  use  water-closets,  these  will  give  rise  to  least  difficulty. 
If  the  dry-earth  closet  system  is  employed,  the  receptacles 
should  be  emptied  at  frequent  intervals.  This  work  is 
often  delegated  to  civilians.  The  latrines  should  not  be 
near  the  kitchen  or  mess-room,  nor  near  the  sleeping- 
quarters  of  the  troops. 

The  kitchens  should  be  in  separate  buildings  from  the 
sleeping-quarters,  or  at  least  removed  from  them  as  far  as 
possible. 

When  numerous  cases  of  tonsillitis  occur  in  barracks, 
deficient  ventilation  may  usually  be  suspected.  The 
accumulation  of  infective  dust,  along  with  vitiated  air,  in 
barracks  is  frequently  the  predisposing  cause  of  tubercu- 
losis and  pneumonia  among  troops. 

Marches. — The  effects  of  marches  are  dependent  upon 
the  distance  covered,  the  rate  of  travelling,  the  load 
carried  by  the  soldier,  the  condition  of  the  weather,  and 
the  character  of  the  roads.  An  important  influence 
upon  the  soldier  during  long  marches  is  the  length  of 
the  step  taken  and  the  number  of  steps  per  minute. 

At  the  end  of  each  hour  a  rest  of  at  least  five  minutes 
should  be  allowed.  This  will  permit  the  fatigued  soldier 
to  recuperate,  at  least  partially,  and  increases  his  endur- 
ance to  a  very  large  extent.  Whenever  possible,  marches 
should  be  made  before  ten  in  the  morning  or  after  five  in 
the  afternoon  if  the  weather  is  warm,  and  the  troops  should 
be  allowed  to  rest  during  the  hottest  part  of  the  day. 

The  canteens  are  to  be  filled  with  water  or  tea  before 
beginning  a  march,  but  no  fluid  should  be  drunk  while 
marching,  or  as  little  as  possible,  and  then  only  in  small 
quantities  at  a  time. 

Under  ordinary  conditions,  both  in  cold  and  hot 
countries,  the  men  are  healthy  on  the  march.  But 
marches  are  sometimes  harmful  : 

I.  When  a  single  long  and  heavy  march  is  undertaken, 
when  the  men  are  overloaded,  without  food,  and  perhaps 
without  water. 


3i8  MILITARY  HYGIENE. 

2.  When  the  marches,  which  singly  are  not  too  long, 
are  prolonged  over  many  days  or  weeks  without  rest. 

3.  When  special  circumstances  produce  disease. 

The  diseases  from  which  the  soldiers  of  the  United 
States  suffer  most  commonly,  in  time  of  peace,  are: 
venereal  diseases,  tonsillitis,  acute  and  chronic  bronchi- 
tis, diarrhea  and  enteritis,  influenza,  alcoholism,  malarial 
fevers,  rheumatism,  measles,  mumps,  tuberculosis.  The 
diseases  which  prevailed  during  the  Spanish-American 
War  were:  malaria,  dysentery  and  diarrhea,  typhoid 
fever,  respiratory  and  venereal  diseases.  The  prevalence 
of  these  diseases  varied  with  the  localities  in  which  the 
troops  were  employed. 

The  diseases  which  cause  the  greatest  number  of 
deaths  in  soldiers  in  time  of  peace  are:  tuberculosis, 
pneumonia,  heart  disease,  typhoid  fever,  nephritis, 
measles,  alcoholism,  appendicitis.  Since  the  compulsory 
immunization  of  all  recruits  has  been  enforced  typhoid 
fever  has  practically  disappeared  from  the  army.  Dur- 
ing the  time  that  the  troops  were  stationed  along  the 
Mexican  border  in  19 16  paratyphoid  fever  appeared  in 
some  of  the  camps.  This  disease  can  be  controlled  to 
the  same  extent  as  typhoid  fever  is  now  controlled  if 
compulsory  immunization  against  paratyphoid  fever 
is  introduced.  This  is  also  probably  true  of  dysentery. 
Cholera  has  been  kept  under  control  in  the  armies  of 
Europe  by  immunization  of  all  the  soldiers. 

Tuberculosis  has  become  a  ver}^  serious  problem  in 
France  and  some  of  the  other  European  countries  since 
the  beginning  of  the  war.  The  disease  prevails  not  only 
among  the  troops  but  also  in  the  civil  population. 
Several  factors  are  responsible  for  this  condition,  namely, 
neglect  of  precautionary  measures  against  the  disease 
before  the  war  as  shown  by  the  high  death-rate  from 
tuberculosis,  especially  the  lack  of  facilities  for  the  treat- 
ment of  either  incipient  or  advanced  cases  in  hospitals, 
sanatoria,  or  dispensaries ;  the  unsanitary  housing  of  the 


CAMP  DISEASES.  319 

civil  population  and  of  the  troops  in  the  trenches;  and 
the  malnutrition  induced  by  the  exigencies  of  the  war. 

Tuberculosis  among  the  troops  can  be  minimized 
by  careful  physical  examination  of  all  recruits  and  by 
greater  attention  to  the  housing  of  the  troops,  especially 
while  they  are  not  serving  in  the  trenches.  The  gravity 
of  the  situation  in  France  is  portrayed  by  Dr.  Herman 
M.  Biggs  in  "The  Survey"  for  May  5,  1907. 

Pneumonia  is  also  a  serious  disease  among  troops 
whenever  they  are  exposed  to  the  conditions  prevailing 
in  the  trenches,  and  especially  where  they  are  housed  in 
unsanitary  quarters  after  leaving  the  trenches.  Where 
troops  are  confined  in  improperly  ventilated  barracks 
or  in  temporary  quarters  that  are  not  so  constructed 
as  to  permit  thorough  ventilation  pneumonia  usually 
prevails  and  claims  a  high  toll. 

Venereal  diseases  are  always  common  in  troops  for 
a  number  of  reasons  and  require  the  constant  vigilance 
of  those  in  authority  to  keep  them  under  control. 

Camp  Diseases. — The  importance  of  h^^gienic 
measures  in  the  army  and  the  destructive  effects  of  dis- 
eases are  clearly  shown  by  the  records  of  the  Civil  War 
1 861-65,  when  the  casualties  of  battle  were  exceeded  four- 
fold by  the  deaths  caused  by  diseases,  the  most  impor- 
tant and  fatal  of  which  were  pneumonia,  typhoid  fever, 
diarrhea,  and  dysentery.  During  the  Spanish- American 
War,  in  spite  of  the  great  advancement  in  our  knowledge 
of  tjie  etiology  and  modes  of  dissemination  of  typhoid 
fever,  a  very  large  proportion  of  the  army  was  rendered 
useless  for  several  months  owing  to  the  prevalence  of 
this  disease  alone. 

The  close  companionship  entailed  by  the  military  ser- 
vice and  the  neglect  of  individual  cleanliness  are  largely 
blamable  for  the  wide  dissemination  of  typhoid  fever, 
diarrhea,  and  dysentery.  Under  these  conditions  it 
would  seem  a  much  greater  degree  of  personal  cleanli- 
ness is  necessary  than  in  private  life.  Another  factor  to 
be  considered  is  the  large  number  of  mild  cases,  the  so- 


320  MILITARY  HYGIENE. 

called  "walking"  cases,  which  prevailed  in  some  of  the 
camps  during  the  late  war.  Aside  from  this  the  influence 
of  infected  dust  and  the  agency  of  flies  and  insects  must 
also  be  taken  into  consideration. 

Antityphoid  Vaccination. — The  practise  of  antityphoid 
vaccination,  first  introduced  into  the  English  army  by 
Sir  A.  E.  Wright,  and  since  adopted  by  the  armies  of 
nearly  all  the  world  powers,  is,  beyond  question,  limiting 
the  incidence  of  the  disease  and  reducing  the  mortality. 
The  adoption  of  this  method  of  protection  for  the  soldiers 
of  the  United  States  army  has  almost  eliminated  the 
sickness-rate  and  the  death-rate  from  typhoid  fever. 

Pfeiflfer  and  KoUe,  in  Germany,  and  Sir  A.  E.  Wright, 
in  England,  in  1896,  demonstrated  that  it  is  possible  to 
immunize  human  beings  against  typhoid  infection  by  the 
injection  of  extracts  of  Bacillus  typhosus  or  by  the  injec- 
tion of  the  bacilli  killed  by  heating  above  their  thermal 
death-point. 

Wright  vaccinated  a  portion  of  the  British  army  sent 
to  Africa  during  the  Boer  war,  and  subsequently  some  of 
the  soldiers  sent  to  Egypt  and  portions  of  the  forces  in 
India  were  also  vaccinated.  The  value  of  these  vaccina- 
tions was  shown  in  the  lowering  of  the  incidence  of 
typhoid  fever  among  the  vaccinated  troops  as  compared 
with  those  not  so  protected,  and  also  in  the  lowering  of 
the  death-rate  among  the  vaccinated  as  compared  with 
that  among  the  unvaccinated. 

Antityphoid  vaccination  in  the  United  States  army  was 
first  carried  out  by  Major  F.  F.  Russell  early  in  the  year 
1909.  At  first  vaccination  was  voluntary,  but  was  made 
compulsory  March  9,  191 1,  for  the  troops  sent  to  Texas 
and  California  along  the  Mexican  border.  June  9,  191 1, 
vaccination  was  made  compulsory  for  all  recruits,  and 
September  30,  191 1,  for  all  persons  in  the  army  under 
forty-five  years  of  age. 

The  vaccine  employed  in  the  United  States  army  and 
navy  is  prepared  from  a  single  culture  (Rawling's)  grown 
in  agar  flasks  for  eighteen  hours.     The  growth  is  washed 


CAMP  DISEASES. 


321 


off  in  a  small  quantity  of  sterile  salt  solution  and  the  sus- 
pension heated  in  a  water-bath  at  53°  to  54°  C.  for  one 
hour.  To  this  is  added  0.25  per  cent,  of  trikresol,  and 
the  suspension  diluted  with  salt  solution  until  a  concen- 
tration of  1,000,000,000  bacilli  to  the  cubic  centimeter  is 
obtained. 

The  vaccine  is  tested  as  to  its  sterility,  purity,  and  for 
the  presence  of  tetanus  bacilli. 

The  vaccine  is  administered  in  three  doses  of  500, 
1000,  and  1000  million  bacilli  at  intervals  of  about  a 
week. 

The  following  table  ^  shows  the  occurrence  of  typhoid 
fever  (1901  to  1912)  for  the  entire  United  States  army, 
officers  and  enlisted  men,  at  home  and  abroad  : 


C 

ases. 

Deaths. 

Occurring  among 

those  who  were 

Mean 
strength. 

Percentage 

vaccinated. 

Year. 

Ratio 

Ratio 

of  total 

No. 

per  1000 

No. 

per  1000 

cases. 

of  mean 

of  mean 

strength. 

strength. 

Cases. 

Deaths. 

1901 

81.885 

SS2 

6.74 

74 

.88 

13.0 

igo2 

80.778 

565 

6 

74 

69 

85 

12 

2 

1903 

67-643 

348 

5 

14 

30 

44 

8 

6 

1904 

67.311 

293 

4 

35 

23 

33 

7 

8 

i9°5 

65.688 

206 

3 

14 

20 

30 

9 

7 

igo6 

65-159 

373 

S 

72 

18 

27 

4 

8 

1907 

62.523 

237 

3 

79 

19 

30 

8 

0 

1908 

74.692 

239 

3 

20 

24 

31 

10 

0 

1909 

84.077 

282 

3 

35 

22 

26 

7 

8 

I 

0 

1910 

81.434 

198 

2 

43 

14 

17 

7 

I 

7 

0 

1911 

82.802 

70 

0 

85 

8 

10 

II 

4 

II 

I 

1912 

88.478 

27 

0 

31 

4 

044 

14.8 

8 

0 

Thus  far  there  have  been  only  27  cases  of  typhoid  fever 
among  the  vaccinated  troops  and  but  i  death.  During 
the  year  191 3  there  were  only  2  cases  of  typhoid  fever 
among  all  the  troops. 

In  the  United  States  navy^  antityphoid  vaccination 
was  made  compulsory  January  i,  1912,  and  the  degree  of 
protection  has  been  equal  to  that  experienced  in  the 
army. 

Pneumonia  and  acute  bronchitis  are  more  prevalent 
during  the  winter  months,  and  these  are  traceable  to 
exposure,    dampness,     imperfect    nutrition,     insufficient 

1  Russell's  Amer.  Jour,  of  Medical  Sciences,  December,  1913,  p.  803. 
'Am.  Rept.  Surg.  Gen.,  1912,  p.  116. 
21 


322  MILITAR  Y  HYGIENE. 

clothing,  these  being  the  most  common  predisposing 
factors.  Rheumatism  also  is  favored  by  the  same  predis- 
posing causes.  - 

In  certain  localities  malarial  fevers  also  prevail  to  a 
considerable  extent  among  soldiers.  This  has  been  the 
case  with  our  soldiers  in  the  tropics.  The  preventive 
measures  which  would  tend  to  render  a  malarious  locality 
healthful  are  draining  of  damp  soil,  pouring  oil  upon  all 
stagnant  bodies  of  water,  the  protection  of  the  soldier  by 
means  of  mosquito-bars  wherever  possible,  and  the  avoid- 
ance of  exposure  after  nightfall. 

In  camps  composed  of  recently  enlisted  soldiers  measles 
is  very  likely  to  make  its  appearance.  Thus  far  no 
definite  mode  of  prevention  can  be  outlined  against  this 
disease  except  the  prompt  isolation  of  cases  as  they 
appear. 

Tuberculosis  is  also  prevalent  among  soldiers.  This 
is  the  case  in  both  camp  and  barrack,  though  in  the 
latter  it  is  encountered  most  frequently. 

Diseases  of  the  heart  and  blood-vessels  are  frequent  as 
the  result  of  the  strenuous  duties  of  the  soldier.  Long 
and  forced  marches  result  in  the  exhaustion  of  those  with 
a  weak  circulatory  apparatus. 

Venereal  diseases  are  always  prevalent  among  soldiers. 
The  prevention  of  these  diseases  is  a  most  difficult  matter, 
because  it  is  impossible  to  control  such  a  large  body  of 
men  in  their  moral  and  social  relations.  Some  good  may 
be  accomplished  by  banishing  all  known  prostitutes  from 
the  neighborhood  of  the  camp. 

Scurvy  is  far  less  frequent  than  formerly,  though  it  is 
not  unknown  even  at  the  present  day.  This  condition 
may  be  prevented  by  proper  regulation  of  the  food- 
supply,  since  it  is  known  to  be  a  disease  due  to  improper 
nutrition.  Fresh  vegetables  and  ripe  fruit  are  the  most 
serviceable  in  this  respect.  In  the  absence  of  sufficient 
supplies  of  these,  the  use  of  lime-juice  and  vinegar  will 
prove  of  great  value. 

Foot  Inspection. — In  the  German  army  the  feet  of 
the   soldiers    are   carefully   examined,    each   man's   feet 


BOD  Y  INSPECTION.  323 

being  inspected  by  one  of  his  company  officers,  a  medi- 
cal officer,  and  the  lazareth  heifer.^  at  least  twice  a  week 
in  barracks,  and  oftener  in  active  field  maneuvers. 
The  method  of  making  this  inspection  is  to  form  the 
companies  in  squads,  standing  upon  tables  or  benches 
sufficiently  high  to  bring  the  feet  directly  under  the  eye 
of  the  inspecting  officer,  and  to  bring  under  his  observa- 
tion any  wincing  or  flinching  when  the  inspected  man 
jumps  to  the  ground  barefoot.  The  inspecting  officer 
passes  down  the  line  carefully  examining  the  front  of  the 
feet  and  legs,  which  are  bared  to  the  knees,  searching  for 
strained  tendons,  blisters,  improperly  cut  nails,  or  un- 
trimmed  corns. 

Having  passed  down  the  line,  the  men  are  about-faced 
and  the  tendo-achilles  carefully  examined,  and  as  they 
raise  one  foot  and  then  the  other  the  soles  are  inspected. 
As  a  man  passes  from  the  table  or  bench  he  leaps  to  the 
ground  and  runs  to  his  shoes  and  stockings.  This  is  to 
show  any  bruised  soles  or  periostitis  of  the  tarsus.  Any 
cases  of  blisters,  improperly  cut  nails,  or  tenosynovitis 
are  at  once  cared  for  by  the  lazareth  heifer.  Those  with 
more  serious  disorders  are  sent  to  quarters  or  hospital. 

At  the  same  time  each  man's  socks  and  boots  are  care- 
fully inspected  as  to  the  degree  of  cleanliness.  As  the 
infantry  regiments  average  in  marching  a  kilometer  in 
ten  minutes,  being  often  pressed  to  a  kilometer  in  from 
seven  and  a  half  to  eight  minutes,  each  man  carrying  27 
kilograms,  this  care  of  feet  is  necessary.  When  tables 
or  benches  are  not  available,  the  trunk  of  a  fallen  tree  or 
a  block  of  stone  is  used  as  a  place  to  conduct  the  in- 
spection. 

Body  Inspection. — The  entire  body  of  every  man  in 
the  German  army  is  inspected  by  a  company  officer  and 
a  medical  officer,  careful  search  being  made  for  any  heart 
lesion,  hernia,  venereal  disorder,  skin  disease,  eczema, 
etc.  This  is  in  order  that  any  physical  defect  that  might 
be  concealed  by  clothing  or  by  the  improper  modesty  or 
wilfulness  of  the  enlisted  man  may  be  carefully  noted, 
cared  for,   and  reported. 


CHAPTER    XIV. 
NAVAL  HYGIENE. 

The  term  naval  hygiene  usually  includes  all  that 
relates  to  maritime  life,  whether  relating  to  war  or  to 
commerce.  In  a  certain  sense  the  application  of  hygienic 
measures  to  such  a  small  and  isolated  community  as 
found  in  a  vessel  is  extremely  simple.  In  modern  ves- 
sels it  is  far  easier  than  in  those  of  even  a  decade  ago. 
The  improvements  in  construction,  arrangement,  and 
equipment  have  had  a  most  salient  influence  upon  the 
health  of  sailors  and  marines,  and  upon  the  comfort  of 
passengers. 

Though  there  have  been  important  advancements  in 
the  construction  and  arrangement  of  vessels,  it  is  still  a 
difficult  matter  to  supply  pure  air  in  sufficient  quantities, 
because  with  the  advancement  in  equipment  there  has 
been  no  relative  increase  of  the  air  space  available  for 
each  person.  The  air  space  on  shipboard  being  neces- 
sarily limited,  the  average  space  per  individual  can  only 
be  indirectly  increased  by  reducing  the  number  of  seamen 
to  the  lowest  point  permissible. 

The  vessel  should  be  as  large  as  possible  with  reference 
to  the  purpose  for  which  it  is  intended,  the  arrangement 
of  machinery  and  cargo  should  be  such  as  to  economize 
the  utilization  of  space,  and  the  size  and  location  of  the 
cabins  should  be  regulated  so  as  to  afford  a  maximum 
amount  of  space  for  each  person.  The  arrangement  of 
cabins  should  be  made  in  such  a  manner  that  it  may  be 
possible  to  secure  complete  isolation  of  any  cases  of  in- 
fectious disease  at  some  point  removed  from  the  seamen 
in  their  usual  duties.  The  amount  of  space  provided  for 
each  seaman  is  greater  than  had  formerly  been  the  case, 
but  even'  at   the  present  time  it   falls  below  theoretic 

324 


VENTILA  TION.  325 

standards.  The  hospital  cabins  should  be  of  greater 
space,  because  they  are  occupied  during  every  hour  of 
the  day.  These  quarters  should  not  be  located  in  the 
forecastle,  but  at  some  point  as  far  removed  from  the 
noise  of  the  machinery  as  possible. 

The  cubic  space  allotted  to  each  marine  on  war  vessels 
has  not  been  accurately  determined  and  no  data  are  avail- 
able on  this  point.  The  fact  that  marines  sleep  in 
hammocks  may  be  the  cause  of  supplying  a  somewhat 
greater  cubic  space  for  them  than  for  sailors  on  vessels  of 
commerce  where  hammocks  are  not  employed. 

With  regard  to  passenger  ships,  the  German  laws  direct 
that  each  between-deck  passenger  have  an  air  space  of  2.85 
cubic  meters,  and  a  floor  space  of  0.45  square  meter.  For 
first-  and  second-class  passengers  no  directions  have  been 
made.  The  English  laws  direct  that  each  man  have  72 
cubic  feet  of  air  space  and  12  square  feet  of  floor  space. 

Ventilation. — In  modern  vessels  propelled  by  steam 
the  introduction  of  forced  ventilation  by  the  use  of  fans 
or  steam  jets  is  a  comparatively  easy  matter.  In  this 
manner  a  definite  air-supply  can  be  assured,  either  by 
propulsion  of  fresh  air  or  extraction  of  the  vitiated  air. 
By  this  method  the  defects  arising  from  the  small  amount 
of  air  space  usually  supplied  can  be  remedied  to  a  great 
extent. 

Accordinsf  to  information  derived  from  the  Bureau  of 
Construction  and  Repair  of  the  Navy  Department  of  the 
United  States,  "All  ships  of  war  are  ventilated  on  two 
principles,  natural  and  artificial.  Natural  ventilation  is 
obtained  through  hatches,  ventilating  ducts,  and  other 
openings  leading  directly  to  the  compartment  to  be  ven- 
tilated, and  depending  upon  a  supply  of  air  through 
cowls  which  are  turned  toward  the  wind.  All  living- 
spaces  are  further  ventilated  artificially,  either  by  means 
of  steam  or  electric  blowers,  which  supply  the  air  to  or 
exhaust  it  from  the  compartments  in  question.  Some 
compartments  are  fitted  with  both  supply  and  exhaust 
blowers,  but  in  general  only  one  system  is  fitted,  a  natural 


326  NA  VAL  HYGIENE. 

exhaust  being  obtained  through  the  hatches  or  other 
openings  into  the  compartment. 

"  No  rules  can  be  given  for  the  cubic  meters  of  space 
allowed  per  man.  This  is  entirely  dependent  upon  the 
design  of  the  ship  and  the  number  of  men  carried.  The 
design  of  the  ventilating  system,  however,  is  such  as  to 
renew  the  air  in  various  spaces  in  certain  intervals  of 
time,  which  may  be  stated  approximately  as  follows: 
General  crew  space,  the  air  to  be  changed  once  in  eight 
minutes;  officers'  quarters,  once  in  twelve  minutes; 
engine-room  or  steering-engine  room  (where  the  air  is 
hot  and  vitiated),  once  in  two  minutes;  dynamo-room, 
once  every  three-fourths  of  a  minute. 

' '  The  supply  of  air  to  a  compartment  depends  not 
only  on  its  capacity  and  the  number  of  men  in  it,  but 
also  upon  the  temperature,  which  in  some  parts  of  the 
ship  is  excessively  high,  and  in  others  is  naturally  low. 
No  figures  on  efficiency  are  available." 

Dr.  Coppinger'  states  that  "the  question  of  air  space 
and  ventilation,  as  applied  to  men-of-war,  has  always 
been  a  difficult  problem,  and  the  progress  of  modern 
naval  architecture,  necessitated  by  altered  conditions  of 
warfare,  tends  in  many  ways  to  make  its  solution  more 
difficult  of  attainment.  Among  these  conditions  may  be 
mentioned  (i)  the  very  great  amount  of  air  space  occu- 
pied by  machinery  and  stores  connected  with  torpedo 
work,  and  (2)  the  introduction  of  water-tight  bulkheads. 
These  latter  partitions  are  a  great  source  of  difficulty  in 
respect  to  obtaining  complete  circulation  of  air  through- 
out the  ship. 

"The  introduction  of  the  turret  and  barbet  system 
of  construction  into  battleships,  with  the  consequent 
reduction  and  almost  complete  abolition  of  apertures  for 
natural  ventilation  by  means  of  ports  and  hatchways, 
has  rendered  necessary  a  very  general  introduction  of  arti- 
ficial ventilation  by  means  of  rotary  fans,  to  supplement 
artificial  ventilation  by  means  of  funnel  and  funnel  casing. ' ' 

^  Trans.  Seventh  International  Congress  of  Hygiene. 


WA  TER-SUPPL  Y.  327 

111  order  to  cool  the  air  between  decks  of  vessels  while 
in  the  tropics,  it  has  been  suggested  that  this  might  be 
accomplished  by  the  aid  of  compressed  air.  This  may  be 
utilized  both  as  a  source  of  motion  for  propelling  the  air 
and  also  to  abstract  heat  when  undergoing  expansion. 

Heating  of  the  Vessel. — The  application  of  steam  to 
navigation  makes  it  possible  to  utilize  the  exhaust  steam 
for  purposes  of  heating.  This  precludes  the  attempt  to 
heat  by  any  other  methods,  and  affords  a  safe  and  satis- 
factory solution  to  this  problem,  which  formerly  gave 
rise  to  such  great  difficulties. 

I/ighting". — The  employment  of  electricity  on  all  large 
modern  vessels  makes  it  possible  to  utilize  this  method  of 
lighting ;  thus  a  great  factor  in  the  vitiation  of  the  air  in 
certain  parts  of  ships  is  removed. 

Cleansing  the  Vessel. — The  excessive  use  of  water 
for  purposes  of  cleansing  should  be  prohibited.  It  was 
formerly  the  custom  to  keep  the  floors  constantly  soaked 
by  the  frequent  washing  of  the  ship,  thus  giving  rise 
to  a  most  unhealthful  condition  from  dampness.  i\. 
satisfactory  degree  of  cleanliness  can  be  maintained  with- 
out the  constant  application  of  copious  amounts  of  water, 
and  with  the  use  of  steam  for  heating  purposes  modern 
vessels  are  much  dryer  than  formerly,  and  consequently 
more  healthful. 

The  interior  of  iron  ships  is  apt  to  be  damp  on  account 
of  the  condensation  of  moisture  on  the  sides  of  the 
vessels.  The  prevention  of  the  condensation  of  moisture 
is  sought  through  the  application  of  paint  containing 
small  particles  of  cork,  or  a  cork  lining.  The  use  of 
wood  in  modern  warships  has  been  avoided  as  much  as 
possible  for  two  reasons:  First,  the  danger  from  fire;  and 
second,  the  disastrous  effects  from  splintering  of  the 
wood  by  perforating  shot.  The  first  objection  to  the  use 
of  wood  is  efficiently  removed  by  the  use  of  fire-proofing 
materials  which  have  lately  come  into  use,  but  the 
second  objection  remains. 

Water-supply. — Great   care   should   be   exercised   in 


328 


NA  VAL  HYGIENE. 


taking  on  board  a  supply  of  pure  and  wholesome  water 
for  culinary  purposes.  In  the  event  of  a  pure  water- 
supply  being  unavailable,  the  necessary  apparatus  should 
be  on  board  for  sterilizing  the  water  or  for  distilling  sea 
water.  Water-closets  and  bath-rooms  should  be  installed 
in  different  parts  of  the  ship,  so  as  to  be  conveniently 
accessible. 

F'ood-supply. — In  the  case  of  ships  of  commerce  it  is 
comparatively  easy  to  maintain  a  fairly  satisfactory  sup- 
ply of  food.  In  the  case  of  war  vessels  the  State  supplies 
prescribed  rations,  which,  however,  can  be  supplemented, 
if  necessary,  by  additional  purchases  when  beyond  the 
base  of  supplies.  Moreover,  modern  war  vessels  are 
equipped  with  refrigerator  appliances,  so  that  fresh  meat 
and  vegetables  may  be  carried  long  distances. 

The  following  is  the  daily  ration  supplied  to  United 
States  marines,  based  upon  the  amounts  supplied  weekly  : 

Biscuit,  cornmeal  or  oatmeal 454  grams. 

Fresh  meat,  or 567 

Tinned  meat,  or 454 

Salted  beef  or  pork      340 

Peas,  beans,  or  tomatoes,  or 227 

Fresh  vegetables,  or 5^7 

Canned  vegetables 170 

Butter 24 

Coffee,  or 57 

Tea,  or I4 

Cocoa 57 

Pickles 32 

Syrup 16 

Vinegar 32 

The  diet  should  be  regulated  so  as  to  avoid  undue  mo- 
notony. The  harmful  influences  of  excessive  amounts 
of  salted  meat  should  be  overcome  by  the  use  of  refrigerated 
or  preserved  meats  and  the  use  of  sufficient  amounts  of 
vegetables  and  fruit.  Besides  guarding  against  the  use 
of  improper  proportions  of  certain  food  elements  at  all 
times,  it  is  necessary  to  adapt  the  dietary  to  the  climate 
as  well  as  to  the  nature  of  the  work  done  by  the  men. 
The  diet  should  at  all  times  be  sufficient  to  nourish  prop- 


SELECTION  OF  MARINES.  329 

erly  the  men  under  whatever  external  conditions  they 
may  be  placed. 

Dr.  Henry  G.  Beyer  ^  calculates  that  the  regular  naval 
ration  affords  daily  142  gm.  nitrogenous  matter,  51  gm. 
fats,  and  398  gm.  carbohydrates. 

On  German  war- vessels  each  man  receives  daily  150 
gm.  nitrogenous  materials,  500  gm.  carbohydrates,  100 
gm.  fats,  35  gm.  salt.  In  the  German  navy  scorbutus  is 
prevented  by  giving  each  man  20  grams  of  citric  acid 
daily  when  the  voyage  is  longer  than  fourteen  days, 
especially  in  the  tropics. 

Clothing". — The  clothing  of  marines  is  adapted  to  the 
climate  of  the  locality  and  the  season  of  the  year.  During 
hot  weather  white  duck  uniforms  are  worn,  while  in  cold 
weather  woollen  clothes  and  underclothes  are  supplied. 
In  the  navy  the  question  of  clothing  does  not  require  the 
same  degree  of  attention  and  forethought  as  is  often  the 
case  in  the  army,  because  each  individual  sailor  is  not 
required  to  carry  his  wardrobe  on  his  back  wherever  he 
goes. 

Selection  of  Marines. — In  the  selection  of  marines 
the  same  careful  physical  examination  is  necessary  as  in 
the  selection  of  recruits  for  the  army.  This  physical 
examination  is  directed  to  the  determination  of  the  age, 
height,  weight,  chest  measurement,  sight,  and  hearing 
of  the  applicant.  As  the  result  of  the  careful  physical 
examination  of  the  nude  bodies  of  6129  lads  applying  for 
admission  to  the  U.  S.  Naval  Academy  at  Annapolis, 
Dr.  Gihon  found  the  following  means  at  different 
ages  (see  page  330) : 

Dr.  Gihon  concludes  that  at  every  age  there  is  a  lati- 
tude of  from  22.5  to  27  kilograms  in  weight,  17.7  to  21.8 
centimeters  in  height,  and  15.2  to  17.7  centimeters  in 
circumference  of  chest,  within  which  over  900  of  every 
1000  adolescents  will  be  found,  and  "it  must  be  recog- 
nized as  a  fact  that  perfect  health  and  bodily  vigor,  and 
the  development  peculiar  to  the  type  and  temperament 

^Proceedings   U.  S.  Naval  Institute,  p.  609,  1899. 


330 


NA  VAL  HYGIENE. 


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SELECTION  OF  MARINES. 


Zl"^ 


oi  the  individual,  are  not  inconsistent  with  an  average 
departure  below  the  mean  of  12  kilograms  in  weight,  10 
centimeters  in  height,  and  7.5  centimeters  in  circumfer- 
ence of  chest. ' ' 

Enlistment  of  boys  in  the  U.  S.  naval  service  is  made 
under  the  following  regulations: 

"  I.  Boys  between  the  ages  of  fifteen  and  seventeen 
years  may,  with  the  consent  of  their  parents  or  guardians, 
be  enlisted  to  serve  in  the  navy  until  they  shall  arrive 
at  the  age  of  twenty-one  years. 

"2.  No  minor  under  the  age  of  fifteen  years,  no  insane 
or  intoxicated  person,  and  no  deserter  from  the  naval  or 
military  service  of  the  United  States,  can  be  enlisted. 

"3.  Boys  enlisted  for  the  naval  service  must  be  of 
robust  frame,  intelligent,  of  perfectly  sound  and  healthy 
constitution,  and  free  from  any  of  the  following  defects: 

"Greatly  retarded  development;  feeble  constitution,  in- 
herited or  acquired;  permanently  impaired  general  health; 
decided  cachexia,  diathesis,  or  predisposition;  weak  or 
disordered  intellect;  epilepsy,  or  other  convulsions  within 
five  years;  impaired  vision  or  chronic  disease  of  the  organs 
of  vision;  great  dulness  of  hearing  or  chronic  disease  of  the 
ears;  chronic  nasal  catarrh;  ozena,  polypi  or  great  enlarge- 
ment of  the  tonsils;  marked  impediment  of  speech;  decided 
indications  of  liability  to  pulmonary  disease;  chronic 
cardiac  affections;  hernia  or  retention  of  testes  in  inguinal 
cavity;  circocele,  hydrocele,  stricture,  fistula,  or  hemor- 
rhoids; large  varicose  veins  of  lower  limbs,  scrotum,  or 
cord;  chronic  ulcers;  cutaneous  and  communicable  dis- 
eases; unnatural  curvature  of  the  spine,  torticollis  or 
other  deformity;  permanent  disability  of  either  of  the 
extremities  or  articulations  from  any  cause;  defective 
teeth ;  the  loss  or  extensive  caries  of  four  molar  teeth. 

"4.  Physical  examinations  will  be  made  by  the  medi- 
cal officer  of  the  ship  upon  which  a  boy  presents  himself 
for  enlistment. 

"5.  Boys  must  have  the  following  heights  and  meas- 
urements: 


332 


NA  VAL  HYGIENE. 


Age. 

Fifteen  years 
Sixteen  years 


Height  not  less  than —    Weight  not  less  than — 


.  4  feet  1 1  inches. 
.  5  feet    I  inch. 


8o  pounds. 
90  pounds. 


Chest  measurement, 
breathing  naturally, 
not  less  than — 

27  inches. 

28  inches. 


' '  6.  They  must  be  able  to  read  and  write. 

"7.  In  special  cases,  where  a  boy  shows  general  intel- 
ligence, and  is  otherwise  qualified,  he  may  be  enlisted 
notwithstanding  his  reading  and  writing  are  imperfect. 

"8.  Bach  boy  presenting  himself  for  enlistment  must 
be  accompanied  by  his  father,  or  by  his  mother  in  case 
the  father  be  deceased,  or  by  his  legally  appointed  guar- 
dian in  case  he  has  neither  father  nor  mother  living,  and 
the  parent  or  guardian  presenting  the  boy  must  sign  the 
prescribed  'Consent,  declaration,  and  oath,'  which 
forms  part  of  the  shipping  articles.    ' . 

"9.  In  cases  where  parents  or  guardians  may,  by 
reason  of  distance,  infirmity,  or  other  causes,  be  unable 
to  appear  at  the  place  of  enlistment,  they  will,  on  writ- 
ten application  to  the  commanding  officer  of  either  of 
the  ships  upon  which  enlistments  are  made,  be  furnished 
with  the  printed  form  of  '  Consent,  declaration,  and 
oath,'  in  duplicate,  by  executing  which  the  enlistments 
will  be  perfected,  should  the  boys  be  accepted  by  the 
board  of  examining  officers. ' ' 

"On  first  enlistment  men  must  be  between  the  follow- 
ing ages: 


Rating.  Years  of  age. 

Seamen 21  to  35 

Ordinary  seamen 18  "  30 

Landsmen 18  "  25 

Shipwrights 21  "  35 

Blacksmiths :  21  "  35 

Plumbers  and  fitters    .    .    .    .  21  "  35 

Sailmakers'  mates 21  "  35 

Machinists,  first  class  .  .  .  21  "  35 
Machinists,  second  class  .  .  21  "  35 
Electricians,  third  class     .    .  21  "  35 

Boilermakers 21  "  35 

Coppersmiths 21  "  35 

Firemen,  first  class     .    .    .    .  21  "  35 


Rating.  Years  of  age. 

Firemen,  second  class     .    .    .21  to  35 

Coal-passers 21  ''  35 

Hospital  stewards 21  "  30 

Hospital  apprentices,  1st  class  18  "  25 
Hospital  apprentices,  2d  class  18  "  25 

Officers'  stewards 21  "  35 

Officers'  cooks 21  "  35 

Mess  attendants 18  "  30 

Ships'  cooks,  fourth  class  .  .  18  "  30 
Musicians,  first  class  .  .  .  .  21  "  35 
Musicians,  second  class      .    .  21  "  35 

Buglers 21  "  35 

Painters 21  "  35 


PRINCIPAL  DISEASES  AMONG  MARINERS. 


333 


"Minimum  height  for  ratings  herein  mentioned,  5 
feet  and  4  inches,  stripped;  the  candidate  should  be  well 
developed,  considering  his  age  and  height, 

"  Persons  possessing  a  mechanical  trade  may  be  enlisted 
even  if  over  twenty-five,  provided  they  are  under  thirty- 
five  3'ears  of  age. 

"  No  person,  except  an  honorably  discharged  ex-appren- 
tice, shall  be  enlisted  as  a  seaman  unless  he  shall  have 
been  four  years  at  sea,  nor  as  an  ordinary  seaman  unless 
he  shall  have  been  two  years  at  sea  before  the  mast.  In 
both  cases  applicants  vshall  be  required  to  pass  a  satis- 
factory examination. ' ' 

The  general  appearance  of  the  applicant  is  also  taken 
into  consideration,  and  those  that  are  uncleanly  in  their 
person  or  attire  are  discarded  because  they  prove  in- 
capable of  efficient  training. 

Recently  the  character  of  the  teeth  in  applicants  for 
both  the  naval  and  military  service  has  been  taken 
into  consideration.  It  is  evident  that  a  man  whose  grind- 
ing and  biting  capacity  is  seriously  impaired  will  more 
readily  suffer  from  gastro-intestinal  trouble  than  one  with 
a  full  set  of  perfect  teeth.  The  loss  of  five  teeth,  absent 
or  unsound  in  any  degree,  is  usually  considered  as  cause 
for  rejection  ;  even  the  loss  of  three  or  four  molars  or  in- 
cisors in  the  same  jaw  is  sufficient  to  render  a  young  man 
unfit  for  service  in  the  navy. 

Principal  Diseases  among  Mariners. — The  average 
strength  of  the  active  list  of  the  U.  S.  Navy  for  the  year 
1899  was  20,019.  The  total  number  of  admissions  for 
disease  was  12,794,  and  for  injuries  2955,  giving  a  ratio 
per  1000  of  strength  of  636.11  and  146.92,  respectively. 
During  the  year  there  were  admitted  to  the  sick  list,  of 
the  total  force — 


Malarial  diseases     ....  943  cases. 

Diarrheal  affections    .    .    .  900      '' 

Wounds 884      '• 

Rheumatic  affections  .    .    .  716      " 

Bronchial  affections     .    .    .  685      " 


Epidemic  catarrh    ....  672  cases. 

Dengue 297      " 

Alcoholism 193      " 

Heat-stroke 154      " 

Typhoid  fever 134      " 


334 


NAVAL  HYGIENE. 


Pneumonia 1 17  cases. 

Pulmonary  tuberculosis  .    .  87      " 

Dysentery 68      '' 

Organic  heart-disease     .    .  42      " 

Measles 37      " 


Nephritis 31  cases. 

Scarlet  fever    ......  29      " 

Yellow  fever 8      " 

Small-pox 6      " 


Of  the  943  cases  of  malarial  diseases,  nearly  one-third 
were  from  the  navy-yard  and  marine  headquarters,  Wash- 
ington, D.  C.  ;  of  the  134  cases  of  typhoid  fever  reported 
during  the  year,  49  were  under  treatment  in  the  naval 
hospital,  Newport,  R.  I.  Of  this  number,  45  originated 
among  the  perso7tnel  of  the  training  station,  i  was  re- 
ceived from  the  torpedo  station,  and  3  from  ships  of  the 
North  Atlantic  squadron. 


CHAPTER   XV. 
SOIL. 

The  nature  of  the  soil  in  its  relation  to  health  is  an 
important  subject.  The  relation  of  the  soil  of  a  locality 
to  the  public  health  is  dependent  upon  its  intimate  struct- 
ure. Soils  are  composed  of  varying  proportions  of  min- 
eral, vegetable,  and  animal  constituents.  These  constitu- 
ents vary  in  size  not  only  in  different  localities,  but  even 
in  the  same  locality.  The  interstices  of  the  soil  are  filled 
either  with  air  or  with  water.  A  soil  is  moist  or  dry 
according  to  the  preponderance  of  small-  or  large-sized 
soil-particles.  The  finer  and  more  uniform  the  soil- 
particles,  the  greater  the  amount  of  moisture  usually 
contained  in  the  soil. 

All  soils  are  porous,  and  contain  varying  amounts  of 
air  and  moisture.  The  relation  of  the  soil  to  health  is 
influenced  by  the  amount  and  nature  of  the  contained  air 
and  water.  The  degree  of  purity  of  the  ground-air  and 
ground-water  is  influenced  by  the  amount  and  nature  of 
the  vegetable  and  animal  organic  matter  contained  in  the 
soil,  and  the  temperature  of  the  locality — whether  favor- 
able or  unfavorable  to  the  decomposition  of  organic 
matter  through  the  agency  of  bacteria. 

Ground-air. — Ground-air  is  usually  rich  in  carbon 
dioxid,  derived  from  decomposing  organic  matter  in 
the  soil.  It  is  also  very  moist,  because  there  is  usually 
plenty  of  opportunity  to  take  up  moisture.  It  also  con- 
tains decomposition-products,  such  as  marsh-gas,  hydro- 
gen sulphid,  and  ammonia.  This  air  is,  consequently, 
not  suitable  for  respiratory  purposes.  The  amount 
of  soil-air  that  gains  access  to  houses  under  ordinary 
conditions  is,  however,  so  small  that  its  influence  prob- 

335 


oog-  SOIL. 

ably  is  not  felt.  In  newly  made  soils,  in  which  there  is 
considerable  decaying  organic  matter,  there  is  some 
danger  of  the  entrance  of  large  amounts  of  ground-air 
into  houses  built  on  such  soils  unless  special  provision 
is  made  to  exclude  it.  In  such  houses  there  should  be 
cemented  foundation  walls  and  cellars,  and  the  supply 
of  fresh  air  should  be  derived  from  the  outside  at  some 
distance  above  the  ground.  Unless  the  foundation  walls 
and  cellars  are  cemented,  the  houses,  when  warmed,  may 
serve  as  immense  chimneys  in  extracting  the  air  from  the 
surrounding  soil. 

Ground- water. — Ground-water  is  rain-water  that  has 
fallen  upon  the  soil  of  the  locality  and  penetrated  its 
surface.  It  differs  from  stored  rain-water  according  to 
the  nature  of  the  soil  constituents.  It  is  richer  in  dis- 
solved solids,  and  contains  also  the  products  of  de- 
composition derived  from  decaying  organic  matter  in 
the  soil.  It  contains  also  numerous  bacteria  derived 
from  the  soil.  The  relation  of  ground-water  to  health  is 
directly  dependent  upon  the  presence  or  absence  of  patho- 
genic bacteria  in  the  soil,  and  the  presence  or  absence 
of  mineral  constituents  derived  from  the  soil  which  may 
be  injurious  to  health,  such  as  salts  of  calcium,  magne- 
sium, or  iron  in  large  amounts. 

Pettenkofer's  theory  of  the  relation  of  soil  moisture  to 
typhoid  fever  and  cholera  is  no  longer  tenable.  We 
know  now  that  the  height  of  the  level  of  the  ground- 
water has  no  direct  influence  in  the  production  of  either 
of  these  two  diseases.  There  is  evidently  an  indirect 
relation  between  low  ground-water  and  the  development 
of  these  diseases,  because  at  such  times  the  drainage  area 
of  all  wells  is  increased,  and  the  polluting  material  in  or 
upon  the  soil  of  a  correspondingly  greater  area  is  con- 
ducted into  the  well.  In  the  same  manner,  when  drink- 
ing-water is  derived  from  streams,  there  is  greater  oppor- 
tunity for  the  entrance  of  concentrated  polluting  matter 
into  the  stream,  and  it  exists  there  in  a  more  concentrated 
form  than  in  times  of  flood. 


GROUND-WATER.  337 

The  relation  of  a  damp  soil  to  the  greater  prevalence 

of  consumption,  as  originally  pointed  out  by  Bowditch, 
cannot  be  regarded  as  a  direct  one.  The  damp  soil  prob- 
ably predisposes  to  colds  and  diseases  of  the  lungs,  and 
thus  paves  the  way  for  the  contraction  of  consumption. 
There  is  thus  far  no  evidence  that  the  bacillus  of  tuber- 
culosis is  capable  of  multiplying  in  damp  soils. 

The  relation  of  damp,  marshy  soils  to  malaria  has 
received  a  great  deal  of  elucidation  in  recent  years.  It 
is  believed  at  the  present  time  that  the  malarial  organ- 
ism is  contracted  most  frequently,  if  not  entirely,  through 
the  sting  of  a  particular  genus  of  mosquito — Anopheles. 
These  mosquitoes  are  usually  indigenous  to  the  soil  of 
certain  marshy  localities,  but  thus  far  no  definite  relation 
between  the  nature  of  the  soil  of  these  localities  and 
the  prevalence  of  mosquitoes  has  been  demonstrated. 
Marshy  localities,  when  drained  so  as  to  prevent  the  de- 
velopment of  mosquitoes,  also  become  healthful  and  free 
from  malaria.  Where  drainage  is  impossible,  it  is  known 
that  the  application  of  some  oil,  such  as  crude  petroleum, 
on  the  surface  of  the  water  will  prevent  the  development 
of  the  mosquitoes  and  thus  eradicate  malaria  from  those 
localities.^ 

Damp  soils  are  likely  to  be  productive  of  diarrheal  dis- 
eases, though  these  affections  are  most  probably  brought 
about  by  certain  bacteria  in  the  soil  along  with  the  detri- 
mental influence  of  the  dampness  itself.  The  amount  of 
decaying  organic  matter  in  and  upon  the  soil  is  most 
probably  in  direct  relation  to  the  prevalence  of  diarrheal 
diseases  in  a  locality. 

Tn  the  same  manner  the  amount  of  moisture  in  the 
soil  will  influence  the  prevalence  of  other  diseases,  such 
as  rheumatism,  bronchitis,  pneumonia,  and  the  exanthem- 
ata. The  relation  of  soil  moisture  to  these  diseases  is 
probably  only  an  indirect  one,  in  that  it  tends  to  lower 

1  Recent  studies  in  Africa-  indicate  that  probably  other  diseases,  especially 
filariasis,  are  conveyed  by  species  of  mosquitoes. 
22 


338  SOIL. 

the  general  vitality  of  the  individuals  living  in  the 
locality. 

Pathogenic  Bacteria  in  Soil. — Some  of  the  patho- 
genic bacteria  are  apparently  capable  of  living  in  the  soil 
for  a  long  time,  and  some  of  them  may  even  be  able  to 
multiply  in  the  soil.  Among  these,  Bacillus  anthracis. 
Bacillus  tetani,  and  Bacillus  oedemas  are  perhaps  most 
'  capable  of  subsisting  in  the  soil  because  of  their  faculty 
of  passing  into  the  spore  stage.  Bacillus  sporogenes  of 
Klein  may  also  be  included  in  this  class. 

Bacillus  typhosus  and  the  cholera  organism  are  less 
tenacious,  and  die  after  a  time  through  the  detrimental 
influence  of  the  soil  organisms.  Bacillus  tuberculosis  can 
remain  alive  in  soil  for  some  time  when  protected  from 
the  influence  of  soil  organisms,  though  the  danger  of 
infection  through  polluted  soil  is  probably  a  remote  one. 
The  pyogenic  cocci  and  the  diphtheria  bacillus  cannot 
exist  in  the  soil  for  any  length  of  time  unless  protected 
from  the  influence  of  the  soil  organisms. 

Improvement  of  a  Damp  Soil. — A  damp  soil  may 
be  improved  by  opening  the  outflow  or  by  laying  a  sys- 
tem of  underground  drains.  The  construction  of  sewers 
often  serves  to  drain  the  soil  to  a  considerable  extent 
because  the  g-round-water  follows  the  outside  of  the 
sewer. 

Configuration  of  the  Surface  and  Soil- covering.— 
Aside  from  the  intrinsic  nature  of  the  soil  itself,  and  the 
character  and  amount  of  air  and  water  contained  in  its 
interstices,  the  healthfulness'  of  a  soil  is  influenced  also 
by  the  configuration  of  the  surface,  the  condition  of  the 
surface,  and  the  nature  of  the  soil-covering.  With  re- 
gard to  the  configuration  of  the  surface,  it  may  be  said 
that,  as  a  rule,  highlands  are  more  healthful  than  low- 
lands. The  degree  of  healthfulness  of  lowlands  is  influ- 
enced by  the  nature  of  the  soil  composing  them.  The  con- 
dition of  the  surface  of  the  soil  with  regard  to  soil-cover- 
ing which  is  least  healthful  is  what  is  known  as  a  desert. 
Here  the  soil  is  exceedingly  dry  and  cannot  be  cultivated. 


SURFACE  AND  SOIL-COVERTNG. 


339 


Cultivated  areas  and  areas  covered  with  forests  are  more 
healthful,  because  the  soil  is  shaded  and  thus  the  heating 
effect  of  the  sun's  rays  is  partly  excluded.  Cultivated 
areas  that  are  thickly  populated  are  less  healthful  because 
of  the  organic  impurities  which  gain  access  to  the  soil. 
The  soil  of  cities  can  be  maintained  in  a  comparatively 
healthful  condition  only  by  systematic  drainage,  so  as  to 
carry  away  all  the  organic  impurities  without  contami- 
nating the  soil,  air,  or  drinking-water. 


CHAPTER   XVI. 
HABITATIONS. 

The  first  consideration  in  the  selection  of  a  site  for  a 
habitation  is  the  nature  of  the  soil  with  regard  to  damp- 
ness and  organic  impurity,  since  these  are  the  principal 
factors  in  rendering  a  soil  unhealthful.  The  house 
should  stand  upon  a  site  the  subsoil  of  which  is  naturally 
dry,  or  is  properly  drained  and  free  from  impurity.  The 
configuration  of  the  surface,  the  elevation,  and  the  ex- 
posure are  important  features  in  rendering  the  locality 
favorable  for  a  healthy  habitation.  The  nature,  source, 
and  amount  of  the  water-supply  should  be  investigated. 
The  possibility  for  the  economic  and  safe  disposal  of  all 
refuse  matter  must  also  be  considered.  The  locality 
should  be  sufficiently  elevated  to  secure  good  drainage 
away  from  the  house.  A  southern  exposure  is  preferable, 
especially  in  colder  climates.  The  proximity  of  large 
bodies  of  water  and  of  marshy  areas  have  detrimental 
influences  upon  the  healthfulness  of  the  locality. 

The  habitation  should  be  so  situated  with  relation  to 
others  surrounding  it  that  an  abundant  supply  of  fresh 
air  and  sunlight  can  be  secured.  The  healthful  influ- 
ences of  sunlight  and  fresh  air  cannot  be  ignored.  The 
absence  of  sunlight  and  deficiency  of  fresh  air  are  the 
most  important  factors  in  inducing  disease  in  the  homes 
of  the  poorer  classes  in  our  large  cities. 

Position  of  the  House. — If  possible,  the  house, 
especially  when  located  on  open  ground,  should  face  the 
south  or  west,  in  order  to  secure  the  greatest  amount  of 
sunlight  in  that  portion  of  the  house  most  constantly 
occupied.  The  windows  require  protection  with  blinds 
and  awnings  in  summer,  to  exclude  the  heat  and  glaring 

340 


THE  ROOF. 


341 


effect  of  the  sun;  but  in  winter  the  full  and  free  action 
of  sunlight  should  be  secured,  at  least  during  a  part  of 
each  day,  because  of  its  purifying  influence  upon  the  air 
of  the  house. 

Foundation  and  Walls. — The  foundations  and  walls 
should  be  as  dry  as  possible,  and  in  damp  soils  this  can 
be  secured  only  by  draining  the  subsoil  below  the  founda- 
tions, and  by  cementing  the  foundation  walls  and  cellar 
floor.  If  there  is  no  cellar,  the  floors  should  be  raised 
about  0.5  meter  above  the  ground,  so  as  to  secure  thor- 
ough ventilation  beneath  the  floor.    Dryness  of  the  walls 


Fig.  57. — Double  foundation  walls. 

is  best  secured  by  means  of  hollow  walls  (Fig.  57),  or  by 
coating  the  walls  with  cement  or  slate.  Bricks  are  quite 
porous  and  absorb  a  great  deal  of  moisture,  and  thus 
render  the  walls  damp.  Stone  also  is  porous  and  retains 
moisture  for  a  long  time,  consequently  stone  houses  are 
liable  to  be  damp. 

The  Roof. — The  roof  of  the  house  must  be  carefully 
constructed  and  frequently  examined  in  order  to  prevent 
leaking.  The  material  composing  the  roof  is  of  no  vital 
importance  so  long  as  it  excludes  rain.  The  rain-water 
falling  upon  the  roof  should  be  conducted  away  from  the 


342  HABITATIONS. 

house,  so  as  to  prevent  the  soil  of  the  locality  from  be- 
coming unduly  damp  from  this  cause. 

The  Interior  Arrangement. — The  interior  of  the 
house  should  be  arranged  so  as  to  afford  the  greatest 
facility  for  the  use  of  every  part  of  it  for  the  purposes  for 
which  it  is  intended.  The  stairways  should  be  wide  and 
the  steps  broad,  with  easy  slope,  so  as  to  prevent  fatigue 
as  much  as  possible  in  going  from  one  floor  to  another. 
The  rooms  on  each  floor  should  communicate  with  each 
other,  or  with  a  common  hallway,  so  as  to  favor  easy 
access  and  insure  more  efiicient  ventilation. 

Si^e  of  the  Rooms. — The  size  of  the  rooms  is  a  mat- 
ter of  the  greatest  importance  in  maintaining  the  purity 
of  the  contained  air.  The  detrimental  influence  of  in- 
sufficient air  space  is  well  known.  The  point  of  greatest 
hygienic  importance  is  not  how  many  rooms  a  person  has, 
but  how  much  room.  A  small  room  may  be  overcrowded 
with  a  single  person  in  it,  while  a  large  room  is  not 
overcrowded  with  four  to  six  persons  in  it.  Aside  from 
the  matter  of  cubic  space,  the  question  of  the  dimensions 
of  the  room  is  of  the  greatest  importance.  The  minimum 
amount  of  cubic  space  allowable  in  sleeping-rooms  per 
adult  person  is  25  cubic  meters.  It  is  evident  that  a 
room  3  meters  high  is  far  more  easily  ventilated  than  one 
that  is  10  meters  high  with  the  same  amount  of  air  space. 
Sleeping-rooms  should  be  at  least  2.75  meters  high, 
though  a  height  much  in  excess  of  3  meters  is  not 
desirable.  A  room  less  than  2  meters  in  height  is  not 
suitable  for  a  sleeping-room.  The  floor  space  of  a  sleep- 
ing-room should  be  at  least  8  square  meters.  The  living- 
rooms  of  a  house  should  possess  a  cubic  space  of  about 
30  cubic  meters. 

If  the  arrangements  for  ventilation  are  efficient,  the 
air  will  require  to  be  changed  about  three  times  an  hour 
in  a  room  of  25  to  30  cubic  meters  capacity,  while  in  a 
room  of  only  10  to  12  cubic  meters  the  air  must  be 
changed  seven  to  eight  times  an  hour  in  order  to  main- 
tain its  purity.     The  living-rooms  of  a  house  should  be 


THE  SLEEPING-ROOMS.  343 

correspondingly  larger  than  the  sleeping-rooms,  in  order 
to  accommodate  the  larger  number  of  persons  occupying 
them,  and  the  greater  amount  of  exhalation  from  the 
body,  and  the  greater  amount  of  impurity  derived  from 
heating  and  lighting.  It  has  been  estimated  that  every 
lighted  gas-burner  requires  from  300  to  400  cubic  meters 
of  fresh  air  per  hour  in  order  to  prevent  an  undue  amount 
of  pollution  of  the  air  of  a  room  from  this  source,  and 
to  maintain  the  standard  of  purity. 

The  Sleeping-rooms. — Lawson  Tait,  on  the  basis  of 
a  lifelong  experience  and  observation,  stated  that  the  bed- 
room should  have  a  capacity  of  56  cubic  meters,  with 
tight-fitting  doors  and  windows,  and  a  ventilating  flue  of 
at  least  1.5  decimeters  in  diameter.  The  window-panes 
should  be  of  plate  glass  to  prevent  the  too  rapid  cooling 
of  the  air  of  the  room.  He  advised  the  construction  of 
houses  with  double  walls,  with  an  air  space  between 
them  of  at  least  o.  75  decimeter,  in  order  to  prevent  damp- 
ness of  the  walls.  If  possible,  the  room  should  be 
warmed  with  gas,  as  this  is  the  best  method  of  maintain- 
ing a  uniform  temperature.  He  directed  that  the  bed- 
stead shall  be  of  steel  or  iron,  2  meters  in  length,  and  of 
a  width  sufficient  to  accommodate  only  one  person.  Two 
such  bedsteads  should  be  placed  side  by  side.  The  dan- 
ger of  communicating  such  a  disease  as  consumption  from 
one  person  to  another  while  sleeping  together  is  quite 
evident.  The  healthfulness  of  single  beds  is  generally 
recognized,  though  in  America,  as  in  England,  they  are 
not  in  very  common  use. 

Since  we  have  learned  the  great  value  of  the  open-air 
treatment  of  tuberculosis  and  other  diseases,  the  advisa- 
bility of  spending  more  of  our  time  in  the  open  air  has 
been  apparent,  and  physicians  are  advising  their  patients 
to  sleep  with  windows  open  all  the  year.  Where  the 
rooms  are  heated  during  the  day  one  may  prepare  for 
bed  in  a  warm  room  and  open  the  windows  on  retiring. 
In  this  way  the  bedclothes  are  kept  warm  and  dry,  and 
there  is  no  danger  in  sleeping  with  the  windows  wide 


344  HABITA  TIONS. 

open  as  long  as  the  sleeper  is  protected  against  tlie  cold 
blasts  of  the  wind.  It  is  necessary  to  guard  against  direct 
draughts  and  to  supply  abundant  bed-clothes.  Under 
these  conditions  sleep  is  far  more  sound  and  refreshing, 
and  the  body  maintains  its  vigorous  state  under  greater 
stress  than  otherwise. 

The  Floors  and  Floor  -  coverings. —  Hard -wood 
floors  are  to  be  preferred,  because  they  are  less  pervious 
to  dust  and  therefore  more  easily  kept  in  a  sanitary  con- 
dition. 

The  covering  of  the  floors  of  a  house  has  an  important 
influence  upon  its  healthfulness.  Carpets  and  matting 
are  objectionable,  because  they  are  fastened  to  the  floor 
and  are  allowed  to  remain  in  place  for  months  or  even 
years.  It  is  preferable  to  have  the  floors  painted  and 
covered  with  a  rug  that  can  be  removed,  aired,  and 
cleaned  at  frequent  intervals. 

The  Wall-covering. — The  covering  of  the  walls  of 
rooms  is  a  matter  of  the  greatest  importance.  Wall- 
paper or  paint  of  a  bright-green  or  red  color  should  be 
avoided,  because  these  colors  may  contain  arsenic.  The 
arsenic  in  wall-papers  will  eventually  become  detached 
and  be  present  in  the  air  of  the  room  as  arsenical  vapor. 
Sufficient  arsenic  has  been  found  in  the  air  of  rooms, 
derived  from  these  sources,  to  produce  poisonous  effects 
in  those  constantly  breathing  the  air.  The  custom  of 
placing  a  new  layer  of  wall-paper  on  the  old  and  soiled 
paper  cannot  be  condemned  too  vigorously.  This  custom 
is  very  generally  practised  in  spite  of  repeated  remon- 
strances and  warnings  of  the  danger  involved.  All  the 
filth  contained  on  the  old  paper  is  allowed  to  remain  on 
the  walls,  and  is  simply  covered  over  with  another  layer 
of  paper.  This  goes  on  until  the  number  of  layers  of 
paper  is  so  great  that  its  weight  prevents  it  from  adhering 
to  the  walls  any  longer.  Whenever  a  room  needs  paper- 
ing, the  old  paper  should  be  carefully  removed  and  the 
walls  scraped  before  a  layer  of  new  paper  is  placed  upon 
them. 


VENTILATION  AND  HEATING.  345 

The  prevalence  of  tuberculosis  in  certain  houses  year 
after  year  and  generation  after  generation  can  be  traced, 
at  least  in  considerable  part,  to  the  custom  of  repapering 
the  walls  without  previously  removing  the  soiled  paper, 
as  well  as  to  neglect  of  disinfection  and  cleansing  after 
death  or  removal  of  a  case  of  tuberculosis.  This  con- 
dition will  continue  until  compulsory  registration  of 
all  tubercular  patients  is  secured.  The  tubercle  bacillus 
is  capable  of  existing  in  the  dust  of  rooms  for  a  long 
time,  and  the  inhalation  of  this  infectious  dust  by  sus- 
ceptible persons  is  no  doubt  a  frequent  source  of  infec- 
tion. When  moving  into  an  old  house,  therefore,  it  will 
be  safest  to  give  it  a  thorough  cleansing  and  disinfection, 
to  prevent  the  contraction  of  disease  from  infected  dust 
and  the  soiled  walls  and  woodwork  of  the  house. 

It  is  preferable  to  have  the  walls  painted,  in  order  that 
they  may  be  cleaned  and  disinfected  without  injury. 
Where  the  delicate  nature  of  the  wall  paint  does  not  per- 
mit efficient  cleansing  and  disinfection  a  fresh  coat  of 
paint  should  be  applied  instead.  This  will  serve  to  dis- 
infect the  walls  in  an  efficient  manner. 

Ventilation  and  Heating:. — When  a  general  system 
of  heating  and  ventilation  is  employed,  by  means  of  a 
furnace  or  indirect  heating  with  steam,  provision  should 
be  made  for  securing  pure,  fresh  outside  air.  The  more 
or  less  stagnant  air  of  the  cellar  should  not  be  employed 
for  this  purpose.  Ventilating  flues  of  appropriate  size 
should  lead  to  each  of  the  rooms,  so  that  the  ventilation 
of  each  may  be  independent  of  every  other  part  of  the 
house.  Provision  must  also  be  made  for  the  escape  of 
the  impure  air  from  each  room,  a  matter  which  is  very 
frequently  neglected. 

When  the  rooms  are  warmed  by  direct  heating  of  some 
form  or  another  it  is  still  necessary  to  provide  for  the  en- 
trance of  fresh  air.  In  such  a  system  of  heating  the  out- 
side air  cannot  always  be  brought  in  at  the  desired  tem- 
perature, and  it  becomes  necessary  to  provide  special 
devices  for  bringing  in  the    fresh   air   without  creating 


346  HABIT  A  TIONS. 

drauglit.  The  fresh  air  cannot  be  brought  in  by  simply 
opening  the  windows  without  creating  draughts.  The 
simplest  method  is  by  placing  a  board  underneath  the 
lower  sash,  so  as  to  allow  the  air  to  enter  between  the 
lower  and  upper  sash  (see  Fig.  8),  In  this  way  the  in- 
coming air  will  continue  its  upward  course  and  become 
distributed  through  the  upper  portion  of  the  room.  A 
number  of  devices  have  been  invented  to  bring  about  the 
same  results  without  the  use  of  a  board  beneath  the  lower 
sash,  among  which  are  perforated  window-panes,  and  an 
upper  sash  that  slopes  inward.  Fresh  air  may  also  be 
admitted  through  special  openings  in  the  walls,  but  in 
this  method  it  is  necessary  to  conduct  the  incoming  air 
upward  toward  the  ceiling,  so  as  to  avoid  draught.  The 
inlet  openings  should  always  be  high  enough  to  prevent 
the  current  of  air  impinging  on  the  occupants  of  the 
room.  In  order  to  secure  efficient  ventilation  where  the 
system  of  indirect  heating  is  employed,  it  is  necessary  to 
provide  exit  openings  for  the  impure  air  in  the  room. 

Cooling'  Devices. — During  the  summer  months  it  is 
frequently  desirable  to  cool  the  air  of  a  room  or  of  the 
entire  house.  For  the  purpose  of  cooling  the  air  of  a 
single  room  small  electric  fans  are  in  very  general  use. 
These  serve  to  propel  the  air  through  the  room  at  a  high 
rate  of  speed,  and  thus  produce  a  cooling  effect  through 
the  greater  evaporation  from  the  surface  of  the  body. 
Recent  experiments  on  human  beings,  confined  in  a 
special  chamber,  demonstrate  that  when  the  air  is  in  a 
highly  vitiated  state  through  the  accumulation  of  the 
products  of  respiration,  the  setting  up  of  active  move- 
ments in  the  air  with  an  electric  fan  will  at  once  relieve 
the  oppression  of  the  occupants. 

The  air  of  an  entire  house  may  be  cooled  by  passing 
it  through  a  chamber  filled  with  ice,  the  air  being  pro- 
pelled throughout  the  different  parts  of  the  house  by  a 
large  fan  or  blower.  This  method  is,  however,  very  ex- 
pensive, as  it  requires  large  quantities  of  ice  or  the  em- 
ployment of  an  ice  machine  of  one  or  more  tons  daily 


COOLING  DEVICES. 


347 


capacity,  according  to  the  size  of  the  house  to  be  cooled 
and  the  initial  temperature  of  the  outside  air.  Passing 
the  incoming  air  through  a  large  screen,  over  which  a 
spray  of  ice-water  is  falling,  will  also  serve  to  cool  the 
air. 

Liquid  air  has  been  employed  as  a  means  of  cooling 
the  air  of  theaters  in  summer  and  has  proved  satisfactory, 
although  this  is  also  an  expensive  method.  Within 
recent  years  Professor  Gates,  of  Washington,  devised  an 


Fig.  58. — The  Nevo.     Front  and  sectional  views. 


apparatus  for  cooling  the  air  which,  it  is  claimed,  can 
be  operated  more  cheaply  than  a  stove.  Professor  Willis 
L.  Moore,  of  the  United  States  Weather  Bureau,  has  also 
devised  an  apparatus  for  this  purpose  called  the  ' '  Nevo ' ' 
(Fig.  58).  This  apparatus  consists  of  a  cylinder  contain- 
ing compartments  filled  with  cracked  ice  and  salt,  through 
which  the  warm  air  descends.  The  cool  air  issues  at  the 
bottom,  and  from  this  point  gradually  mingles  with  the 
air  of  the  room.     The  higher  the  outside  temperature, 


348  HABITA  TIONS. 

the  greater  the  volume  of  air  which  passes  through  the 
apparatus.  Different  sizes  of  this  apparatus  adapted  for 
use  in  single  rooms  or  larger  apartments  are  now  on  the 
market. 

Plumbing  and  Drainage. — The  character  of  the 
plumbing  and  drainage  of  urban  houses  has  a  direct  in- 
fluence upon  the  health  of  the  occupants.  All  the 
appliances,  such  as  sinks,  water-closets,  and  bath-tubs, 
should  be  supplied  with  appropriate  traps,  in  order  to 
exclude  the  drain-air.  These  traps  are  now  generally 
required  by  the  sanitary  laws  of  all  large  municipalities, 
and  the  form  and  character  of  the  traps  to  be  employed 
are  frequently  stated  in  these  laws.  While  the  danger 
from  sewer-air  spoken  of  in  the  older  text-books  is  greatly 
exaggerated,  it  is  well  known  that  such  air  must  be 
rigidly  excluded  from  houses  to  avoid  any  possible  in- 
jurious effects.  Continued  breathing  of  air  containing 
the  considerable  quantities  of  carbon  dioxid  found  in 
sewer-air,  besides  the  other  putrefactive  gases  present  in 
it,  will  eventually  prove  injurious. 

The  plumbing  should  serve  to  bring  into  the  house  an 
abundant  supply  of  water  and  distribute  it  to  all  parts  for 
convenient  use.  The  drainage  system  should  be  so  con- 
structed as  to  remove  promptly  and  safely  all  sewage  and 
waste  water  from  the  house. 

Houses  for  the  Poor. — The  overcrowded  condition 
and  unhealthful  character  of  the  habitations  of  the  poor 
have  called  forth  special  regulations  governing  this  mat- 
ter in  many  large  cities.  The  causes  which  have  led  to 
overcrowding  are  numerous,  the  principal  being  (i)  the 
necessity  of  living  near  their  work,  (2)  the  high  price 
of  land  arising  from  the  same  fact,  (3)  the  higher  taxes 
and  rents  resulting  from  the  same  conditions,  and  (4) 
limited  means,  which  prevent  them  from  living  under 
better  conditions. 

In  recent  years  this  condition  of  overcrowding  has 
been  greatly  diminished  through  the  influence  of  several 
factors,   such  as  (i)  the  employment  of  electricity  as  a 


HOUSES  FOR    THE  POOR.  349 

motive  power  for  street  railways.  By  this  means  the 
cost  of  travelling  has  been  diminished,  the  speed  of  the 
cars  has  been  increased,  and  the  lines  of  travel  have  been 
extended  into  the  suburbs  of  cities,  where  cheaper  and 
more  healthful  houses  can  be  procured.  (2)  The  destruc- 
tion by  the  municipal  authorities  of  the  more  objection- 
able of  the  overcrowded  tenements.  (3)  The  regulation 
of  the  size,  construction,  and  arrangement  of  all  new 
dwellings  through  legislation.  One  of  the  most  efficient 
ways  of  preventing  overcrowding  is  to  be  sought  in  afford- 
ing better  communication  between  the  periphery  and 
center  of  a  city,  so  that  those  working  in  the  city  are  not 
compelled  to  live  there,  but  make  it  possible  for  them  to 
live  in  the  suburbs. 

According  to  the  investigations  of  J.  Bertillon,^  the 
population  of  Paris  is  distributed  in  the  following  man- 
ner :  149  per  1000  live  in  overcrowded  dwellings,  363 
per  1000  have  insufficient  room,  266  per  1000  have  suffi- 
cient room,  and  222  per  1000  have  more  than  sufficient 
room. 

According  to  the  same  authority,  the  proportion  of 
population  living  in  overcrowded  dwellings  in  the  larger 
European  cities  is  as  follows  : 

280  per  1000  of  the  Berlin  population. 

200       "  "       London  " 

310       "  "       Moskow  " 

460       "  "       St.  Petersburg         " 

740       "  "       Budapest  " 

Of  the  Paris  population,  378  per  1000  have  2  persons 
per  family,  687  per  1000  have  4  persons  per  family,  753 
per  1000  have  7  persons  per  family,  and  295,000  out  of 
947,000  families  consist  of  only  i  person  ;  and  369,000 
out  of  942,000  dwellings  have  i  room. 

Municipal  legislation  regulating  the  construction  of 
workingmen's  homes  should  prescribe  the  size  of  the 
rooms,   the  number  of  square  meters  of  floor  space   for 

^  Jiev.  d'  Hyg.,  vol.  xxi.,  p.  588. 


3  5  o  HABITA  TIONS. 

each  occupant,  and  the  amount  of  window  surface  in  re- 
lation to  the  floor  surface.  The  regulations  should  also 
direct  the  character  of  the  drainage  facilities  that  are  to 
be  supplied. 

In  many  European  cities  the  construction  of  new  houses 
is  so  regulated  as  to  prohibit  the  utilization  of  more  than 
a  definite  proportion  of  the  ground  surface  for  building 
purposes.  This  feature  prevents  the  construction  of 
houses  in  too  close  proximity  to  adjoining  houses.  In 
many  of  these  regulations  the  height  of  the  houses  is 
regulated  by  the  width  of  the  streets  on  which  they  front, 
or  the  section  of  the  city  in  which  they  are  located.  For 
instance,  in  Bonn,  a  city  with  50,000  inhabitants,  the 
smallest  size  of  the  yards  in  the  business  section  is  25  per 
cent,  of  the  ground  surface  for  buildings  one  story  in 
height,  and  35  per  cent,  for  buildings  more  than  one 
story  in  height,  and  the  greatest  height  allowed  is  20 
meters.  In  the  residence  portion  of  the  city  the  smallest 
size  of  the  yards  is  25  per  cent,  for  houses  of  one  story  in 
height,  and  50  per  cent,  for  houses  of  more  than  one 
story  in  height,  and  the  greatest  height  allowed  is  17 
meters. 

Building  regulations  should  also  include  the  require- 
ments of  lodging-  and  boarding-houses,  because  it  is  in 
these  that  a  great  degree  of  overcrowding  is  found.  These 
regulations  should  state  the  amount  of  cubic  space  that 
must  be  allowed  for  each  lodger,  according  to  age,  and 
the  arrangements  for  the  efficient  ventilation  of  the  rooms 
that  are  necessary  to  secure  a  continuous  supply  of  pure 
air.  These  regulations  should  also  provide  for  the  gen- 
eral sanitary  supervision  of  the  premises  and  arrange- 
ments by  competent  inspectors. 

House-cleaning-. — From  the  fact  that  living  bacteria 
may  be  contained  in  the  dust  of  rooms  the  method  of 
house  cleaning  is  of  importance.  Great  care  should  be 
exercised  to  avoid  disseminating  collections  of  dust  on 
horizontal  surfaces.  All  the  furniture,  woodwork,  and 
painted  walls  should  be  wiped  carefully  with  a  dampened 


PROTECTION  FROM  FLIES  AND  MOSQUITOES.    35  I 

cloth,  in  order  to  remove  the  dust  without  causing  it  to 
rise  into  the  air  of  the  room. 

The  vacuum  cleaner  makes  house-cleaning  less  of  a 
drudgery  than  formerly,  and  at  the  same  time  permits  the 
cleaning  to  be  accomplished  without  raising  volumes  of 
dust,  as  is  done  by  sweeping.  Where  the  house  is  wired 
for  electric  lighting  it  is  possible  to  use  light,  portable 
vacuum  cleaners,  which  clean  floors  and  floor  coverings, 
walls,  and  furniture  in  an  efiicient  and  sanitary  manner. 

The  rugs  on  the  floor  should  be  removed  from  time  to 
time  and  thoroughly  dried  and  cleaned.  The  floors 
should  be  waxed  and  polished  before  replacing  the  rugs. 
Special  preparations  have  been  perfected  for  this  purpose. 
These  are  applied  by  means  of  a  long-handled  brush  and 
then  rubbed  into  the  floor  by  means  of  a  large  burnisher. 
Some  of  these  floor  preparations  contain  turpentine,  or 
other  antiseptic  substances,  and  serve  a  useful  purpose  in 
addition  to  preserving  the  quality  of  the  floor. 

Protection  from  Flies  and  Mosquitoes. — Since  flies 
are  frequent  carriers  of  disease,  they  should  be  rigidly 
excluded  from  the  house.  Flies  feed  on  filth,  and  in 
this  manner  their  bodies  may  become  soiled  with  patho- 
genic bacteria,  and  they  no  doubt  carry  these  bacteria 
from  place  to  place  and  contaminate  whatever  they  light 
upon.  During  the  Spanish-American  War  the  spreading 
of  typhoid  fever  from  one  portion  of  a  camp  to  another 
was  probably  in  part  due  to  this  mode  of  dissemination 
of  the  typhoid  bacillus.  During  the  summer  months, 
therefore,  all  the  doors  and  windows  should  be  fitted  with 
efficient  mosquito-bars,  in  order  to  exclude  flies  and 
mosquitoes.  The  experiences  of  the  several  commissions 
which  have  been  sent  to  malarious  localities  in  Africa, 
Italy,  and  India  have  demonstrated  the  fact  that  simply 
excluding  mosquitoes  from  habitations  by  means  of 
mosquito-bars  serves  to  protect  the  occupants  against 
malarial  infection. 


CHAPTER  XVII. 
VITAL  CAUSES  OF  DISEASE. 

The  vital  causes  of  disease  are  those  vegetable  and 
animal  organisms  which  are  capable  of  existing  as  para- 
sites in  or  upon  the  human  host,  and  by  their  mere 
presence,  or  through  the  production  of  poisonous  prod- 
ucts, cause  disease.  The  vegetable  organisms  producing 
disease  are  of  two  classes — the  bacteria,  and  various 
fungi  which  produce  local  affections  of  the  skin.  Fortu- 
nately, only  a  small  proportion  of  the  bacteria  found  in 
nature  are  pathogenic.  A  number  of  the  specific  dis- 
eases, however,  have  been  traced  to  the  activity  of  these 
organisms.  All  of  these  pathogenic  organisms  are  trans- 
missible from  one  individual  to  another  if  not  already 
immune.  One  attack  of  certain  of  these  specific  dis- 
eases confers  immunity  against  subsequent  infection  from 
the  same  species  of  organism.  In  some  instances  this 
immunity  is  permanent,  lasting  throughout  life,  while  in 
other  diseases  it  is  of  short  duration,  lasting  only  a  few 
weeks  or  months.  The  specific  organisms  of  each  dis- 
ease differ  in  their  morphologic  and  biologic  characters 
from  those  causing  other  diseases  to  such  an  extent  that 
they  can  be  recognized  and  isolated. 

The  micro-organisms  which  are  pathogenic  for  man, 
and  the  specific  organisms  of  the  following  diseases,  have 
be^n  discovered  and  isolated,  as  follows: 

1839,  parasite  of  favus  ; 

1863,  bacillus  of  anthrax — Davaine  ; 

1873,  spirochsete  of  relapsing  fever — Obermeier ; 

1875,  bacillus  of  malignant  oedema — Pasteur  ; 

1878,  actinomyces  bovis — Bollinger  ; 

1879,  micrococcus  of  gonorrhea — Neisser ; 

352 


VITAL  CAUSES  OF  DISEASE. 


n  ^  -J 


1880 
1880 
1880, 
1881 
1882 
1882 
1882 
1882 
1883 
1883 
1884 
1884 
1884 
1884, 
1885 
1885 
1886 
1886 
1887 
1889 
1892 
1894 
1894 
Weeks 

1895 
1897 
1897 
1900 
1902 

1905 
1906 

1906 


Plasmodium  malarias — Laveran; 

micrococcus  lanceolatus  (pneumonia) — Sternberg; 

bacillus  of  typhoid  fever — Eberth; 

micrococcus  tetragenus — Koch  and  Gaffky; 

bacillus  pyocyaneus — Gessard; 

bacillus  of  tuberculosis — Koch; 

bacillus  of  glanders — Loffler  and  Schiitz; 

bacillus  of  rhinoscleroma — von  Fisch; 

streptococcus  pyogenes — Fehleisen ; 

bacillus  lanceolatus — Friedlander  and  Frobenius; 

vibrio  of  x^siatic  cholera — Koch; 

staphylococcus  aureus  and  albus — Rosenbach; 

bacillus  of  diphtheria — Klebs  and  Loffler; 

bacillus  of  tetanus — Nicolaier; 

staphylococcus  citreus — Passet ; 

bacillus  vulgaris — Hauser; 

bacillus  coli — Escherich ; 

bacillus  aerogenes — Escherich ; 

micrococcus  intracellularis — Weichselbaum ; 

bacillus  capsulatus — PfeifFer; 

bacillus  of  influenza — Pfeiffer; 

bacillus  of  bubonic  plague — Yersin  and  Kitasato; 

bacillus    of    infectious    conjunctivitis  —  Koch- 


bacillus  botulinus — Van  Ermengen; 

bacillus  sporogenes — Klein; 

micrococcus  melitensis — Bruce; 

bacillus  mortiferus — Harris; 

trypanosoma  gambiense — Button  ; 

spirochseta  pertenuis — Castellani ; 

spirochseta  pallida — Schaudinn  and  Hoffmann; 

spirochseta  duttonii,  Breinl. 
In  the  following  diseases  no  specific  organisms  have  as 
yet  been  isolated,  though  from  their  clinical  manifesta- 
tions and  contagious  character  they  are  believed  to  be 
due  to  some  specific  agent:  Varicella,  measles,  scarlet 
fever,  whooping-cough,  mumps,  dengue,  typhus  fever, 
yellow  fever,  and  rheumatism.     A  variety  of  micro-or- 

23 


354  VITAL   CAUSES  OF  DISEASE. 

ganisms  has  been  found  in  most  of  these  diseases,  though 
none  of  them  has  been  positively  demonstrated  as  specific. 
Modes  of  Dissemination.^Those  diseases  which  are 
infectious  may  be  disseminated  in  several  different  ways. 
The  confusion  which  is  more  or  less  prevalent  with 
regard  to  the  exact  term  to  employ  in  each  disease, 
whether  infectious  or  contagious,  has  led  numerous 
writers  to  abandon  one  or  the  other  term.  Since  all  con- 
tagious diseases  are  infectious,  it  seems  preferable  to 
abandon  both,  and  to  substitute  the  term  transmissible, 
as  has  been  done  by  Dr.  Abbott,^  and  call  those  diseases 
which  were  formerly  designated  as  contagious,  trans- 
missible by  direct  contact,  and  those  diseases  which  were 
formerly  designated  as  infectious,  transmissible  by  indi- 
rect contact.  Diseases  like  small-pox,  measles,  and  scar- 
let fever  are  transmissible  by  direct  contact;  and  diseases 
like  typhoid  fever  are  usually  transmissible  by  indirect 
contact. 

Some  of  the  diseases,  however,  which  are  frequently 
disseminated  by  direct  contact  may  be,  and  often  are,  dis- 
seminated indirectly  through  the  medium  of  food  infected 
with  the  specific  micro-organisms,  or  through  the  agency 
of  flies  or  other  insects  whose  bodies  have  become  infected 
by  coming  in  contact  with  infective  materials.  A  num- 
ber of  diseases,  prominent  among  which  are  those  due  to 
animal  parasites,  are  disseminated  through  the  use  of 
meat  derived  from  infected  animals,  through  water  pol- 
luted with  animal  excrement,  or  through  green  vege- 
tables that  have  come  in  contact  with  such  excrement. 

In  addition  to  diseases  transmitted  by  the  methods 
indicated,  there  are  some  diseases  in  which  the  infective 
agent  passes  one  of  its  cycles  in  the  body  of  an  insect, 
and  is  disseminated  through  the  bite  of  such  infected 
insect.  The  disease  which  is  best  known  as  being  dis- 
seminated in  this  manner  is  malaria,  which  is  dissemin- 
ated through  the  bite  of  infected  anopheles,  while  filaria- 
sis  is  believed  to  be  disseminated  through  the  bite  of 
another  mosquito,  a  species  of  culex,  and  the  recent 
1  The  Hygiene  of  Transmissible  Diseases. 


NATURE   OF  EPIDEMICS.  355 

studies  upon  yellow  fever  show  conclusively  that  this 
disease  is  disseminated  through  the  bite  of  another  mos- 
quito— stegomyia  fasciata. 

In  the  light  of  the  discoveries  in  regard  to  the  mode  of 
dissemination  of  malaria,  filariasis,  and  yellow  fever  by 
mosquitoes,  and  the  dissemination  of  Texas  cattle  fever, 
the  spotted  fever  of  the  Bitter  Root  Mountains,  and 
African  tick  fever  by  ticks,  and  sleeping  sickness  by  the 
tsetse  fly,  it  is  safe  to  predict  that  other  diseases  will  be 
found  to  be  disseminated  by  somewhat  similar  agencies. 
There  is  no  doubt  that  in  the  immediate  future  the  in- 
vestigations of  scientists  will  be  directed  toward  the  dis- 
covery of  such  disseminating  agencies,  and  with  the  dis- 
covery of  such  agencies  the  causes  of  these  diseases,  as 
yet  undetermined,  may  likewise  be  discovered,  and  our 
measures  of  prevention  placed  upon  a  more  satisfactorx- 
basis. 

Nature  of  Epidemics. — The  opinions  of  authorities 
differ  with  regard  to  the  number  of  cases  of  any  infectious 
disease  that  may  exist  in  a  community  before  the  disease 
may  be  declared  to  be  epidemic  in  its  character.  A  few 
isolated  cases  are  usually  spoken  of  as  an  "outbreak" 
of  the  disease;  but  when  the  number  of  cases  amounts  to 
I  per  1000  of  the  population,  it  is  usually  said  to  be 
epidemic.  In  England,  measles  is  said  to  be  epidemic 
when  the  number  of  cases  amounts  to  1.2  per  1000  of  the 
population.  Some  years  ago  yellow  fever  was  said  to  be 
epidemic  when  the  number  of  deaths  from  that  disease 
exceeded  the  number  from  all  other  causes.  ]More  recently 
the  disease  was  considered  epidemic  in  New  Orleans  when 
there  were  between  2000  and  5000  cases,  or  about  22  per 
1000  of  population.  Usually  when  10  cases  of  any  dis- 
ease develop  in  close  proximity  to  each  other,  when  all 
sanitary  precautions  have  been  exercised,  the  disease  is 
said  to  be  epidemic. 

A  disease  is  said  to  be  epidemic  when  the  infection  has 
been  imported  into  a  locality  and  spreads  over  an  area. 
A  disease  is  said  to  be  epidemic  when  it  develops  within  a 
locality,  or  is  peculiar  to  a  locality,  and  spreads  over  an 


3S6  VITAL   CAUSES  OF  DISEASE. 

area.  A  disease  is  said  to  be  pandemic  when  it  spreads 
over  very  large  areas  or  prevails  in  several  continents  at 
the  same  time.  The  term  pande7nic  disease  is  usually 
applied  to  cholera,  yellow  fever,  influenza,  and  plague. 
The;  different  pandemic  diseases  have  local  habitats  from 
which  they  are  rarely  or  never  absent.  The  habitat  of 
influenza  is  in  Russia,  that  of  cholera  in  the  valley  of 
the  Ganges  River,  that  of  plague  in  Indo-China,  and  that 
of  yellow  fever  in  countries  bordering  on  the  Gulf  of 
Mexico  and  Caribbean  Sea. 

Imtnunity  and  Susceptibility. — When  we  undertake 
to  investigate  the  causative  factors  underlying  the  results 
of  the  exposure  of  an  entire  community  to  a  source  of 
infection,  with  the  idea  of  ascertaining  the  reasons  why 
a  certain  proportion  of  such  a  community  escapes  the 
infection,  a  number  of  questions  of  great  practical  im- 
portance present  themselves.  We  are  frequently  satis- 
fied in  solving  these  questions  by  saying  that  those  mem- 
bers of  the  community  which  escaped  the  disease  did  so 
from  the  fact  that  they  were  not  susceptible,  or,  probably, 
that  they  were  immune,  and  that  those  who  contracted 
the  disease  were  susceptible,  or  that  they  were  not  im- 
mune. 

It  will  be  necessary  to  consider  briefly  what  is  meant 
by  the  terms  susceptibility  and  immunity,  and  then  we 
shall  better  understand  why  such  differences  in  effects 
manifest  themselves. 

Immunity  may  be  described  as  that  condition  of  the 
body  in  which  it  resists  the  invasion  of  disease-producing 
bacteria,  or  resists  their  growth  and  activity  after  they 
have  gained  an  entrance ;  while  susceptibility  is  a  con- 
dition in  which,  instead  of  the  resistance  of  the  body 
overcoming  the  action  of  the  invading  parasites,  the  par- 
asites overcome  the  resistive  forces  of  the  body  and  dis- 
ease results. 

Immunity  is  either  natural  or  acquired.  Natural  im- 
munity is  the  inherent,  vital  reaction  of  a  healthy  or- 
ganism against  the  invasion  of  disease-producing  bacteria. 
There  is  greater  susceptibility  of  some  races  to  certain  dis- 


IMMUNITY  AND  SUSCEPTIBILITY.  357 

eases  than  to  others.  Also  there  may  be  a  family  resist- 
ance transmitted  from  generation  to  generation,  or  it  may 
be  individual. 

The  principal  factors  upon  which  natural  immunity 
depends  are  the  following :  (i)  The  normal  fluids  of  the 
body  are  germicidal  either  through  the  presence  of  acids 
or  through  the  presence  of  bactericidal,  agglutinative, 
opsonic,  and  antitoxic  substances,  which  can  always  be 
detected  in  the  blood  in  limited  amounts.  (2)  The  skin 
and  mucous  membranes  are  so  constructed  as  to  prevent 
the  invasion  of  bacteria.  (3)  Those  bacteria  which  escape 
the  foregoing  defensive  agents  of  the  body  may  be  taken 
up  and  destroyed  by  the  phagocytes  after  they  have  been 
acted  upon  by  the  opsonins. 

This  natural  immunity,  in  man  as  well  as  in  animals, 
is  frequently  destroyed  through  external  agencies,  such 
as  changes  in  the  nature  and  quantity  of  the  food-supply, 
changes  of  modes  of  living,  as  from  outdoor  occupations 
to  indoor  occupations,  undue  exposure,  close  confinement 
through  lack  of  sunshine  and  fresh  air,  as  well  as  many 
other  changes  in  the  environment  which  tend  to  lower  the 
general  vitality  of  the  system.  By  modifications  in  the 
activity  and  environment  of  the  lower  animals  it  is  often 
possible  to  render  them  susceptible  to  the  action  of  cer- 
tain bacteria  which  do  not  affect  them  normally. 

Acquired  immunity  maybe  divided  into — (<^)  Naturally 
acquired,  that  induced  by  recovery  from  a  previous  at- 
tack of  a  disease,  as  is  the  case  with  some  of  the  common 
diseases  of  childhood,  as  rubeola,  scarlatina,  and  vari- 
cella. One  attack  of  these  diseases  usually  confers  im- 
munity for  life.  That  induced  by  an  attack  of  an  allied 
disease,  as  in  the  immunity  conferred  by  vaccinia  against 
variola.  {8)  Artificially  acquired,  that  induced  by  the 
injection  of  antitoxin  or  a  mixture  of  toxin  and  anti- 
toxin, as  in  diphtheria  or  tetanus.  That  induced  by  the 
injection  of  vaccine,  as  in  the  protection  against  typhoid 
fever,  dysentery,  cholera,  and  plague  by  means  of  dead 
cultures  of  the  specific  organisms  of  these  diseases.  It 
has  been  demonstrated  over  and  over  again  in  epidemics 


358  VITAL   CAUSES  OF  DISEASE. 

of  diphtheria  that  the  injection  of  small  doses  of  anti- 
toxin into  children  exposed  to  infection  serves  to  break 
up  the  epidemic.  The  latter  form  of  artificially  acquired 
immunity  is,  however,  of  short  duration,  lasting  only 
from  one  to  two  months.  The  immunity  acquired  through 
injection  of  a  mixture  of  toxin  and  antitoxin  or  through 
the  injection  of  a  vaccine  is  termed  "active"  immunity, 
while  that  conferred  by  means  of  antitoxin  is  "passive" 
immunity,  because  the  body  takes  no  part  in  its  develop- 
ment. The  immunity  developed  as  the  result  of  the  em- 
ployment of  vaccines  is  active  in  character,  though  it 
probably  does  not  last  as  long  as  does  the  immunity  ac- 
quired through  recovery  from  an  attack  of  the  disease. 

With  equal  propriety  we  may  speak  of  susceptibility 
as  being  either  natural  or  acquired.  Susceptibility  may 
be  said  to  have  been  acquired  when  disease  is  contracted 
because  of  the  lowered  tone  of  the  body  through  the  in- 
fluence of  the  many  factors  which  tend  to  destroy  natural 
immunity.  This  is  especially  the  case  in  children  when 
an  attack  of  some  acute  infectious  disease  follows  before 
convalescence  from  some  other  disease  has  been  com- 
pleted. 

A  number  of  theories  have  been  proposed  to  explain 
the  phenomena  of  acquired  immunity,  but  some  of  the 
earlier  ones  have  been  found  to  be  erroneous  and  are  no 
longer  tenable.  A  few  of  the  more  important  of  these 
may  be  briefly  stated  before  taking  up  those  which  are 
held  at  the  present  day.  The  first  is  the  "exhaustion" 
theory  proposed  by  Pasteur  in  1880,  which  assumed  that 
through  the  growth  of  the  bacteria  in  the  body  they  de- 
stroyed some  substance  essential  to  their  life  and  so  made 
subsequent  growth  of  the  same  species  of  bacteria  impos- 
sible in  such  an  individual,  the  complete  destruction  of 
this  substance  in  the  body  conferring  complete  immunity. 
Another  theory,  known  as  the  "retention"  theory,  pro- 
posed by  Chauveau  about  the  same  time,  which  assumed 
that  some  product  of  the  vital  activity  of  the  bacteria  was 
retained  in  the  system  which  was  prejudicial  to  the  sub- 
sequent development  of  the  same' species.      Both  of  these 


IMMUNITY  AND  SUSCEPTIBILITY.  359 

theories  have  now  been  discarded  as  affording  no  satis- 
factory explanation  of  acquired  immunity.  Besides  these, 
another  theory  has  been  proposed  which,  while  presenting 
considerable  evidence  in  explanation  of  the  phenomenon, 
was  not  generally  accepted  because  it  failed  to  meet  all 
the  conditions.  This  is  the  "phagocytosis"  theory,  pro- 
pounded by  Metchnikoffin  1884.  He  demonstrated  that 
certain  cells  of  the  body — the  connective-tissue  cells  and 
the  leukocytes — have  the  power  of  absorbing  living  bac- 
teria from  the  fluids  and  tissues  of  the  body.  This  fact 
can  be  very  readily  demonstrated  experimentally  by  inoc- 
ulating certain  bacteria  into  animals.  The  presence  in 
the  blood  of  enormous  numbers  of  leukocytes  at  certain 
stages  of  many  bacterial  diseases  is  likewise  a  strong  indi- 
cation that  they  have  important  functions  to  perform  in 
these  diseases.  According  to  this  theory,  the  extent  of 
the  affinity  of  the  leukocytes  for  the  bacteria  is  directly 
dependent  upon  the  degree  of  immunity.  After  taking 
up  the  bacteria  the  leukocytes  are  carried  in  the  blood- 
current  to  the  large  glandular  organs,  the  liver  and 
spleen,  where  they  are  probably  destroyed  along  with 
their  contained  bacteria,  or,  in  the  case  of  wounds,  they 
are  cast  off  as  pus  with  the  other  debris  resulting  from 
the  disease-process. 

The  studies  of  Sir  A.  E.  Wright  and  his  associates 
have  strengthened  the  ' '  phagocytosis ' '  theory  of  Metchni- 
koflf,  and  it  is  now  evident  that  the  phagocytic  powers  of 
the  leukocytes  are  due  to  the  presence  of  certain  antibodies 
in  the  blood — the  opsonins — which  first  act  upon  the 
bacteria  and  prepare  these  for  ingestion  by  the  leukocytes. 
In  some  of  the  bacterial  diseases  this  type  of  immunity 
is  of  primary  importance  and  constitutes  the  more  impor- 
tant factor  in  the  restoration  of  health.  In  other  diseases 
phagocytosis  plays  a  secondary  role  to  other  agents  in  the 
destruction  of  the  invading  micro-organisms.  Such  facts 
as  the  foregoing  have  demonstrated  that  acquired  im- 
munity in  the  different  diseases  is  not  due  to  the  same 
factors,  but  is  specific  in  each  disease. 


360  VITAL  CAUSES  OF  DISEASE. 

Another  theory  proposed  to  explain  immunity  is  known 
as  the  "humoral"  theory,  and  has  been  advanced  by 
Buchner.  It  is  well  known  that  the  serum  of  normal 
individuals  has  the  power,  to  a  considerable  extent,  of  de- 
stroying bacteria,  and  on  this  fact  Buchner  based  his 
theory  that  the  pathogenic  bacteria  are  destroyed  within 
the  body  by  the  bactericidal  action  of  the  blood-plasma, 
and  not  by  the  leukocytes.  Many  of  the  normal  fluids  of 
the  body  also  possess  this  bactericidal  action  to  a  certain 
extent,  Buchner  has  applied  the  term  alexins  to  the 
bactericidal  proteid  substances  of  the  blood.  Detailed 
studies  upon  the  bactericidal  influences  of  blood-serum 
have  demonstrated  that  this  effect  is  due  to  the  pres- 
ence of  two  substances,  as  will  be  seen  in  the  elucidation 
of  Ehrlich's  theory  of  immunity. 

In  1895  Pfeiffer  published  some  experiments  upon  the 
effects  of  the  peritoneal  fluid  of  an  animal  immune 
against  cholera  upon  the  cholera  organisms.  He  demon- 
strated that  if  an  animal  was  rendered  immune  to  cholera 
and  then  received  an  injection  of  cholera  organisms  into 
its  peritoneal  cavity,  the  injected  organisms  underwent 
rapid  deterioration  and  were  completely  destroyed  in  a 
short  time.  These  experiments  demonstrated  that  immu- 
nity against  the  bacteria  themselves  was  due  not  to  pro- 
tective substances  normally  present  in  the  body,  but  to 
something  which  had  developed  during  the  course  of 
immunization. 

The  demonstration  by  Bordet,  in  1896,  that  one  .species 
of  animal  could  be  immunized  against  the  blood  of 
another  species,  and  when  so  immunized  the  blood-serum 
of  the  immune  animal  was  capable  of  dissolving  the  red 
blood-corpuscles  of  the  species  with  whose  blood  it  had 
been  immunized,  opened  up  a  new  field  of  research  which 
has  afforded  most  valuable  information  upon  the  subject 
of  immunity  in  general. 

Ehrlich's  Hypothesis. — In  the  light  of  our  later  knowl- 
edge upon  the  subject  Ehrlich,  in  1898,  formulated  his 
hypothesis  of  the  mechanism  of  immunity  which  is  re- 


IMMUNITY  AND  SUSCEPTIBILITY.  361 

ceiving  very  general  acceptance  by  scientists  to-day. 
His  theory  of  the  mechanism  of  immunity  is  based  upon 
Weigert's  teaching  of  the  process  of  tissue  repair.  It  is 
a  matter  of  universal  observation  that  nature  is  prodigal 
in  her  attempts  to  repair  an  injury.  This  is  shown  in 
the  healing  process  in  an  ordinary  wound.  A  much 
larger  amount  of  material  is  thrown  out  to  bridge  the 
chasm  than  is  really  utilized  in  the  formation  of  new 
tissue.  The  presence  of  an  excessive  amount  of  new 
material  is  shown  by  the  fact  that  the  part  is  raised 
above  the  level  of  the  surrounding  sound  tissue,  and  this 
excess  is  removed  gradually  as  the  newly  formed  tissue 
becomes  stronger  and  stronger,  until,  finally,  the  wound 
is  marked  by  a  line  of  white  scar  tissue,  the  excess  gradu- 
ally passing  into  the  blood  current. 

Ehrlich  believed  that  the  mechanism  of  immunity  was 
explainable  on  a  similar  basis.  It  had  become  evident 
from  the  experiments  of  Wassermann  with  the  tetanus 
bacillus  that  its  toxin  had  an  especial  affinity  for  the 
cells  of  the  central  nervous  system.  Experiments  with 
other  bacteria  pointed  to  the  fact  that  the  toxins  of  dif- 
ferent species  of  bacteria  had  an  especial  affinity  for  the 
cells  of  different  organs  of  the  body.  When  the  amount 
of  poison  entering  the  body  is  insufficient  to  destroy  the 
cells  which  have  an  especial  affinity  for  it,  these  cells 
may  be  injured  only  to  such  an  extent  as  to-  permit  sub- 
sequent repair.  In  order  to  comprehend  Ehrlich' s  hy- 
pothesis, it  is  necessary  to  conceive  the  cells  of  the  body 
as  having  a  complex  structure  which  may  be  stated  dia- 
grammatically  as  consisting  of  a  central  mass  or  nucleus 
from  which  radiate  a  number  of  "side  chains,"  or  lateral 
bonds,  each  of  which  serves  to  bind  the  cell  to  other  sub- 
stances. In  the  case  of  the  cells  of  the  central  nervous 
system  one  of  these  lateral  bonds  has  an  especial  affinity 
for  tetanus  toxin  and  suffers  destruction.  The  cell  now 
finds  itself  in  unstable  equilibrium,  and  at  once  proceeds 
to  repair  the  damage  wrought.  As  in  the  case  of  tissue 
repair,  the  new  material  produced  to  repair  the  breach  is 


362  VITAL  CA  USES  OF  DISEASE. 

far  in  excess  of  the  required  amount.  The  excess  finds 
its  way  into  the  blood-current.  This  material  now  circu- 
lating in  the  blood-current  has  the  same  affinity  for 
tetanus  toxin  as  when  united  with  the  central  mass  of  a 
cell  as  its  lateral  bond,  and  can,  therefore,  combine  with 
tetanus  toxin  floating  in  the  blood-current,  thus  preserv- 
ing other  cells  from  injury.  The  union  formed  between 
the  lateral  bond  of  the  cell,  which  is  really  the  antitoxin, 
and  the  tetanus  toxin  results  in  the  formation  of  a  com- 
pound which  is  physiologically  inert.  According  to  Ehr- 
lich's  idea,  therefore,  the  antitoxin  is  simply  the  excess 
of  lateral  bonds  floating  in  the  blood-current.  This  sub- 
stance can  neutralize  the  effect  of  the  tetanus  toxin  in  a 
test-tube  just  as  readily  as  it  does  within  the  body. 

This  hypothesis  of  the  mechanism  of  immunity  has  been 
very  materially  strengthened  by  the  extension  of  Bordet's 
experiments  upon  the  immunization  of  animals  with  alien 
bloods  which  Bhrlich  made  in  collaboration  with  Morgen- 
roth.  From  the  results  of  these  studies  he  has  broadened 
his  theory  of  immunity  so  that  it  serves  to  explain  certain 
facts  which  were  previously  not  fully  comprehensible. 
Ehrlich  recognizes  three  types  of  immunity  which  differ 
in  their  mechanism  according  to  the  nature  of  the  sub- 
stance employed  in  the  immunization.  Any  protein  sub- 
stance which  exerts  an  injurious  effect  upon  the  body- 
cells  finds  in  these  cells  side  chains  with  which  it  can 
unite.  These  side  chains  are  called  "receptors,"  and 
different  kinds  of  receptors  unite  with  different  forms  of 
foreign  substances. 

I.  In  the  immunity  conferred  by  toxins,  when  anti- 
toxins are  formed,  Ehrlich  conceives  the  receptors  to  be 
of  the  simplest  nature,  and  he  calls  these  uniceptors,  or 
receptors  of  the  first  order.  These  receptors  possess 
simply  one  bond  of  attachment  to  which  the  toxin  unites. 
These  bonds  of  attachment  he  calls  "  haptophores, "  be- 
cause they  may  be  compared  with  prehensile  arms.  Simi- 
larly the  toxin  molecule  also  possesses  a  haptophore  group 
through  which  it  becomes  attached  to  body-cells  and  ex- 


IMMUNITY  AND  SUSCEPTIBILITY.  363 

erts  its  destructive  action.  When  toxin  and  antitoxin 
are  mixed  z';z  vitro  in  equal  proportions,  they  unite  with 
each  other  by  means  of  their  combining  arms,  and,  in 
consequence,  the  toxin  is  neutralized. 

2.  In  the  immunization  of  animals  with  such  substances 
as  milk  there  is  formed  in  the  blood  of  the  immune  ani- 
mal a  substance  which  exerts  a  coagulating  action  when 
mixed  with  milk  of  the  same  species  with  which  the 
immunization  was  brought  about.  This  coagulation  is 
produced  by  receptors  circulating  in  the  blood  of  the  im- 
mune animal.  These  receptors  differ  somewhat  from 
those  of  the  first  order  in  that  they  possess,  in  addition  to 
the  haptophore  group,  a  zymophore  group  (so  called  from 
its  enzyme-like  capabilities)  which  brings  about  the  co- 
agulation.   This  constitutes  the  second  order  of  receptors. 

Receptors  of  a  similar  character  are  formed  in  the 
immunization  of  animals  with  serous  fluids  of  other  spe- 
cies. When  the  blood-serum  of  such  an  immune  animal 
is  mixed  in  a  test-tube  with  the  serum  of  the  species  of 
animal  furnishing  the  blood  for  the  immunization,  a  pre- 
cipitate is  formed.  This  test  has  now  become  of  valua- 
ble service  in  medicolegal  work  in  the  detection  of  human 
blood.  Old  dried  clots  of  blood  can  be  taken  up  in 
physiologic  salt  solution  and  mixed  with  the  serum  of 
an  animal  immunized  with  human  blood.  If  the  blood- 
clot  was  of  human  origin,  a  precipitate  will  be  formed. 
This  is  now  the  most  delicate  test  that  can  be  applied  for 
the  detection  of  human  blood.  Animals  immunized  wdth 
albuminous  human  urine  give  similar  reactions  to  those 
immunized  with  whole  blood  or  with  blood-serum  of 
human  origin. 

3.  Ehrlich's  studies  of  the  mechanism  of  the  immunity 
conferred  by  an  alien  blood  revealed  the  fact  that  if  the 
blood-serum  of  an  animal  immunized  against  an  alien 
blood  was  heated  to  56°  C.  for  half  an  hour,  it  lost  its 
hemolytic  power,  but  that  this  serum  could  again  be  ren- 
dered active  by  the  addition  of  a  drop  of  normal  blood- 
serum.    This  fact  demonstrated  that  the  hemolytic  power 


364  VITAL   CAUSES  OF  DISEASE. 

of  the  immune  serum  was  dependent  upon  two  sub- 
stances :  the  one  present  in  normal  blood  and  destroyed 
by  a  low  degree  of  heat,  and  the  other  present  only  in 
the  serum  of  the  immune  animal  and  more  resistant  to 
heat.  The  first  substance  he  named  the  "  complement," 
because  of  its  complementary  action  to  the  second  sub- 
stance, which  he  called  the  "immune  body."  He  be- 
lieves the  complement  to  be  of  the  nature  of  an  enzyme, 
and,  therefore,  the  substance  through  which  the  immune 
body  really  brings  about  the  solution  of  the  corpuscles. 
In  his  later  communications  Ehrlich  calls  the  immune 
body  the  amboceptor.  This  name  is  indicative  of  the 
two  combining  arms  or  haptophores  possessed  by  the  im- 
mune body,  the  one  serving  to  unite  it  with  the  comple- 
ment, which  he  calls  the  complementophilic  haptophore, 
and  the  other,  the  cytophilic  haptophore,  serving  to  unite 
it  with  the  blood-corpuscle,  bacterium,  epithelial  cell, 
etc.,  against  which  the  animal  has  been  immunized. 

In  the  immunization  of  animals  with  bacteria,  blood- 
corpuscles,  epithelial  cells,  etc.,  there  is  formed  a  recep- 
tor having  two  haptophores — amboceptor  or  immune 
body.  These  are  receptors  of  the  third  order.  This 
amboceptor  is  specific  for  the  particular  cells  employed 
in  the  immunization.  If  the  animal  has  been  immun- 
ized with  the  red  blood-corpuscles  of  another  species,  the 
amboceptor  has  the  property  of  uniting  with  the  erythro- 
cytes of  that  species  of  animal  by  one  of  its  haptophores, 
while  with  the  other  haptophore  it  unites  with  the  com- 
plement of  the  blood-serum  and  brings  about  solution  of 
the  corpuscles — hemolysis.  The  same  effect  is  produced 
when  the  serum  of  an  animal  immunized  with  typhoid 
organisms  is  mixed  with  such  organisms  in  a  test-tube. 
The  amboceptor  unites  with  the  bacilli  with  one  of  its 
haptophores,  while  with  the  other  it  unites  with  the  com- 
plement existing  in  the  blood-serum  and  brings  about 
the  destruction  of  the  organism — bacteriolysis.  Immune 
serums  which  have  been  produced  through  the  immuni- 
zation of  an    animal    with    erythrocytes    are   known   as 


IMMUNITY  AND  SUSCEPTIBILITY.  365 

hemolytic  serums,  while  those  produced  through  the 
immunization  of  an  animal  with  certain  species  of  bac- 
teria are  known  as  bacteriolytic  or  bactericidal  sera.  A 
bacteriolytic  serum  produced  by  the  immunization  of  an 
animal  with  Bacillus  typhosus  may  be  called  a  typhoid- 
immune  serum,  while  a  serum  produced  by  the  immuni- 
zation of  an  animal  with  Bacillus  dysenterise  may  be 
called  a  dysentery-immune  serum,  each  serum  being 
specific  for  the  organism  with  which  the  animal  has  been 
immunized. 

The  hemolytic  and  bacteriolytic  sera  contain,  in  addi- 
tion to  the  specific  amboceptor,  another  receptor  which 
is  regarded  as  being  of  the  second  order,  since  it  exerts 
an  agglutinating  effect  upon  the  cells  with  which  the 
animal  has  been  immunized.  This  receptor  is  instru- 
mental in  bringing  about  the  agglutination  of  the  cells 
used  in  the  immunization,  and  hence  is  called  "  agforlu- 
tinin."  The  Gruber-Widal  reaction,  which  is  now  so 
commonly  employed  in  the  diagnosis  of  certain  diseases, 
rests  upon  the  activity  of  this  substance.  When  an  im- 
mune serum  containins:  ag^orlntinin  is  mixed  with  the 
bacteria  employed  in  the  immunization,  it  brings  about 
the  clumping  of  the  organisms  which  constitutes  the 
Gruber-Widal  test. 

The  complement  or  enzyme-like  element  of  the  blood- 
serum,  which  destroys  the  bacteria  when  brought  in  con- 
tact with  them  through  the  intermediation  of  the  ambo- 
ceptor, is  a  normal  constituent  of  the  blood.  Ehrlich 
and  his  followers  have  demonstrated  conclusively  that 
there  is  a  multiplicity  of  complements  in  normal  blood. ^ 
According  to  Ehrlich' s  conception  of  the  mechanism  of 
immunity,  the  haptophores  of  the  amboceptor  and  com- 
plement must  fit  each  other  like  lock  and  key,  so  that 
unless  both  are  of  like  configuration,  they  cannot  unite. 
Fortunately,  the  human  complements  conform  to  those 
of  the  domestic  animals  to  a  marked  degree,  so  that  ani- 

^  Ehrlich  and  Sachs,  Berlin,  klin.  Wochenschr.,  1902. 


366  VITAL  CAUSES  OF  DISEASE. 

mals  of  this  character  may  be  employed  for  the  purpose 
of  preparing  immune  serum. 

The  Antitoxic  Sera. — It  must  be  borne  in  mind  that 
each  of  the  different  antitoxins  known  is  specific  for  only 
one  kind  of  poison,  and  this  must  be  quite  evident  if 
Ehrlich's  theory  as  to  the  mode  of  formation  of  anti- 
toxins holds  true.  We  know  that  in  chemistry  we  have 
only  one  particular  compound  formed  when  we  mix  sil- 
ver and  hydrochloric  acid  together,  and  for  the  same 
reason  each  particular  toxin  or  poison  can  lead  to  the 
formation  of  only  one  kind  of  antitoxin,  and  this  anti- 
toxin can  probably  neutralize  only  that  particular  kind 
of  poison. 

The  antitoxin  which  is  best  known  to-day  and  which 
is  most  successfully  employed  as  a  therapeutic  agent  is 
that  of  diphtheria.  Diphtheria  is  a  distinctly  toxic  dis- 
ease ;  the  symptoms  and  lesions,  except  those  at  the  seat 
of  infection,  are  almost  entirely  due  to  the  action  of  the 
toxin  circulating  in  the  blood.  The  fever,  debility,  and 
the  paralysis  occurring  during  convalescence  are  probably 
entirely  due  to  the  action  of  the  toxin.  The  bacilli  are 
found  in  the  membranous  exudation  forming  upon  the 
fauces,  and  occasionally  in  the  later  stages  of  the  disease 
they  are  found  in  the  lungs  and  the  heart's  blood. 

Tetanus  is  also  a  purely  toxic  disease.  The  tetanus 
bacillus  appears  to  be  localized  at  the  point  of  inocula- 
tion where  it  produces  its  toxin.  The  toxin  is  taken  up 
by  the  peripheral  nerves,  and  through  these  reaches  the 
central  nervous  system,  for  which  it  has  an  especial 
affinity.  It  is  possible  to  produce  an  efficient  antitoxin 
against  tetanus,  but,  on  account  of  the  affinity  of  the 
toxin  for  the  cells  of  the  central  nervous  system,  the  anti- 
toxin has  proved  of  less  signal  benefit  in  the  treatment 
of  the  disease  than  is  the  case  in  diphtheria.  By  the 
time  tetanic  symptoms  manifest  themselves  in  tetanus 
such  large  numbers  of  the  cells  of  the  central  nervous 
system  have  been  injured  by  the  toxin  that  the  antitoxin 
frequently  fails  to  preserve  life.      The  subdural  adminis- 


IMMUNITY  AND  SUSCEPTIBILITY.  367 

tration  of  the  antitoxin  appears  to  give  the  most  favorable 
results  because  it  brings  the  antitoxin  into  closer  prox- 
imity to  the  injured  nerve-cells. 

Probably  the  most  signal  benefit  of  the  tetanus  anti- 
toxin has  been  as  a  propln-lactic  when  administered  early 
before  the  manifestation  of  tetanic  symptoms  in  suspected 
cases  of  tetanus.  There  is  at  present  no  very  positive 
method  of  determining  the  probability  of  infection  by 
the  tetanus  bacillus,  and  hence  the  use  of  the  tetanus 
antitoxin  as  a  prophylactic  is  largely,  if  not  entirely, 
empirical. 

The  Bacteriolytic  Sera. — Antibodies  are  found  in  greater 
or  lesser  amounts  in  the  blood  of  individuals  suffering 
from  the  different  bacterial  diseases,  and  scientists  have 
for  a  number  of  years  been  engaged  in  the  study  of  the 
problems  connected  with  the  commercial  production  of 
immune  sera. 

In  several  bacterial  diseases,  as  in  typhoid  fever,  chol- 
era, and  to  a  large  degree  in  dysentery,  the  immunity 
is  of  a  bacteriolytic  character,  in  that  the  blood-serum  of 
convalescents  contains  much  greater  amounts  of  the  spe- 
cific amboceptors  than  are  found  in  the  blood  of  normal 
individuals. 

Typhoid  Immune  5erum. — Among  the  earlier  experi- 
menters who  studied  the  production  of  a  typhoid  immune 
serum  are  Lewin^  and  Jez,^  and  their  results  appeared  to 
be  quite  promising.  Beumer  and  Pfeiffer  ^  were  able  to 
show  that  their  serum  had  not  only  immunizing  powers, 
but  also  curative  powers. 

Among  the  attempts  to  perfect  an  immune  serum  for 
typhoid  fever  the  work  of  Chantemesse'*  is  of  interest. 
His  recent  report  on  the  subject  is  most  encouraging, 
covering  as  it  does  the  work  of  six  years.  He  reports 
that  in  the  1000  patients  subjected  to  this  method  of 
treatment  during  the  past  six  years   the   mortality  was 

^  Deutsche  medicinische  IVochenschrift,  January  19,  1899. 
'  Wiener  medicinische  IVochenschrift^  February  18,  1S99. 
^  Zeitschrift  fi'ir  klinische  Medicin,  Bd.  xxviii. 
^  U Hygiene  Gen.  et  Afpliqttee,  October,  1907. 


368  VITAL  CAUSES  OF  DISEASE. 

4.3  per  cent.,  while  the  mortality  in  5621  patients  treated 
at  the  other  hospitals  of  Paris  during  this  period  was 
17  per  cent.  These  patients  all  received  hydrotherapy 
in  addition  to  the  serum  treatment  to  control  the  tem- 
perature. In  the  hands  of  Brunon  and  of  Josias  this 
method  gave  equally  good  results,  and  at  the  military  hos- 
pital of  Val-de-Grace  there  were  but  five  deaths  in  ninety 
cases  so  treated,  the  mortality  for  the  preceding  six  years, 
before  the  introduction  of  the  serum  treatment,  being 
10.6  per  cent.  Chantemesse  emphasizes  the  importance 
of  using  the  serum  as  early  as  possible,  stating,  in  fact, 
that  he  has  never  seen  a  fatal  result  when  the  patient 
received  the  serum  within  ten  days  of  the  onset  of  the 
disease. 

The  serum  of  Chantemesse  is  obtained  from  horses, 
which  for  long  periods  have  been  injected  with  filtered 
and  sterilized  cultures  grown  on  bouillon  of  beef  spleen. 
The  dose  of  the  serum  is  from  one  to  five  drops,  given 
under  the  skin.  After  such  an  injection  there  follows  a 
period  of  reaction,  when  the  temperature  seldom  falls  and 
frequently  is  somewhat  elevated.  The  general  condition 
is  not  improved  during  this  reaction,  which  lasts  from  a 
few  hours  to  several  days.  Chantemesse  regards  this 
phenomenon  as  the  result  of  the  destruction  of  the  bacilli 
in  the  body  and  the  consequent  release  of  an  additional 
amount  of  toxin.  A  study  of  the  influence  of  the  serum 
on  the  opsonic  power  of  the  blood  indicates  that  the  bac- 
tericidal action  of  the  serum  is  in  large  part  due  to  its 
stimulating  effect  on  this  phenomenon.  The  opsonic 
index  is  found  to  be  increased  to  a  greater  degree  in 
severe  infections  than  in  the  mild  ones,  and  for  this 
reason  Chantemesse  advises  using  a  minimum  dose 
of  the  serum  in  severe  cases,  as  the  greater  the  bac- 
tericidal power  of  the  blood,  the  greater  will  be  the 
reaction. 

Following  the  period  of  reaction  comes  a  period  of  def- 
ervescence, when  the  temperature  falls  gradually  and  the 


IMMUNITY  AND  SUSCEPTIBILITY.  369 

condition  of  the  patient  is  in  every  way  improved.  The 
pulse  is  slowed,  the  blood-pressure  is  raised,  the  quantity 
of  urine  is  notably  increased,  and  the  patient  feels  much 
more  comfortable.  The  temperature  usually  continues 
to  fall  for  ten  or  twelve  days,  when  it  may  remain  station- 
ary for  a  few  days  and  then  go  on  to  a  rapid  convalescence 
or  a  mild  relapse.  The  influence  of  the  serum  seems  to 
have  been  exhausted  by  this  time,  and  a  second  injection 
may  be  required.  An  interesting  observation  was  a  very 
definite  increase  in  the  splenic  dullness,  which  is  seen  after 
about  twenty-four  hours.  This  is  a  part  of  the  general 
stimulation  of  the  lymphoid  and  myeloid  tissue  which 
has  been  shown  to  be  the -result  of  the  serum  in  experi- 
mental animals. 

Burroughs,  Wellcome  &  Co.,  London,  manufacture  an 
antityphoid  serum  which  is  obtained  from  horses  that 
have  been  treated  with  killed  cultures  of  Bacillus  ty- 
phosus. 

The  Opsonic  Sera — The  immunity  against  the  pyogenic 
bacteria,  against  pneumococcus,  against  plague  bacillus, 
and  against  tuberculosis  is  not  bacteriolytic  to  any  de- 
gree, but  is  almost  entirely  opsonic  in  character.  The 
opsonins  prepare  these  bacteria  for  destruction  by  the  body- 
cells,  principally  by  the  polymorphonuclear  leukocytes. 

Antistreptococcus  Serum — The  clinical  application  of 
Marmorek's  earlier  antistreptococcus  serum  was  not  very 
encouraging  because  of  the  absence  of  uniformly  positive 
results  and  on  account  of  the  large  doses  required.  The 
conviction  gradually  gained  prominence  that  the  principal 
cause  for  the  uncertain  results  obtained  with  Marmorek's 
serum  was  explainable  on  the  ground  of  the  heterogenicity 
of  the  streptococci  in  different  disease  conditions.  So 
firmly  has  this  conviction  been  established  that  for  the 
past  few  years  the  antistreptococcus  sera  on  the  market 
have  been  prepared  with  organisms  isolated  from  different 
disease  conditions.  This  is  especially  true  of  the  earlier 
sera  prepared  by  Aronson,  Tavel,  Deneys,  Paltauf,  and 
Moser. 

24 


370  VITAL  CAUSES  OF  DISEASE. 

The  prophylactic  and  therapeutic  vahie  of  antistrep- 
tococciis  serum  is  still  under  dispute;  some  investigators 
claim  distinct  prophylactic  and  curative  values,  while 
others  dispute  the  efficacy  of  this  serum,  for  instance, 
Zangemeister^  states  that  he  has  been  unable  to  ob- 
tain any  definite  effects  when  the  serum  was  employed 
either  as  a  protective  agent  against  wound  infection, 
and  still  less  so  when  used  after  infection  had  taken 
place.  On  the  other  hand,  we  find  in  the  literature  on 
this  subject,  frequent  statements  as  to  the  prophylactic 
and  therapeutic  value  of  the  antistreptococcus  serum  in 
isolated  cases,  for  instance,  Fromme^  reports  on  investi- 
gations carried  out  in  the  Halle  Maternity  Clinic,  and 
states  that  as  a  prophylactic  Menzer's  serum  was  very  sat- 
isfactory. In  the  treatment  of  cases  of  endometritis  the 
serum  also  had  a  beneficial  effect;  though  in  streptococcus 
peritonitis  it  seemed  to  be  without  effect,  nor  did  it  seem 
to  be  of  any  value  in  cases  of  pyemia. 

Marmorek  prepares  two  kinds  of  antistreptococcus 
seruin:  {a)  By  the  treatment  of  horses  with  living  cul- 
tures of  streptococcus  ;  (^)  by  the  treatment  of  horses 
with  the  toxin  produced  by  the  streptococci.  In  order 
to  meet  the  conditions  more  certainly  a  mixture  of  the 
two  sera  is  administered. 

Tavel,  Menzer,  and  Moser  employ  living  cultures  of 
streptococci  which  are  secured  from  different  pathologic 
conditions.  These  cultures  are  maintained  at  their  origi- 
nal degree  of  virulence  by  cultivation  in  suitable  media. 
Marmorek,  Aronson,  Denys,  and  Paltauf  prepare  their 
sera  with  cultures  that  have  been  passed  through  animals. 

Aronson  at  first  employed  cultures  of  streptococcus  that 
had  been  rendered  highly  virulent  by  repeated  passage 
through  animals.  The  studies  of  Meyer,  as  well  as  his 
own  later  studies,  convinced  Aronson  of  the  definite  dif- 
ference between  the  effects  of  a  serum  prepared  with 
organisms  that  had  been   rendered  highly  virulent  for 

^  Deutsche  med.  Wochenschrift,  1906,  p.  1077. 
^  Miinchener  med.  Wochenschrift,  1906,  p.  20. 


IMMUNITY  AND  SUSCEPTIBILITY.  371 

animals  and  a  serum  prepared  from  the  same  organisms 
without  passage  through  animals.  Aronson  now  pre- 
pared two  kinds  of  serum  :  [a)  By  immunizing  horses 
with  organisms  of  unaltered  virulence  ;  and  {b)  by  immu- 
nizing horses  with  organisms  raised  to  a  high  degree  of 
virulence  by  passage  through  animals. 

Moser's  serum  is  prepared  with  cultures  obtained  from 
cases  of  scarlet  fever.  The  use  of  this  serum  in  the  treat- 
ment of  scarlet  fever  is  said  to  be  of  considerable  value, 
though  it  is  recognized  that  streptococci  are  not  the 
causative  factors  of  the  disease,  but  merely  contributor}^ 
factors. 

Antistreptococcus  serum  is  also  marketed  by  Bur- 
roughs, Wellcome  &  Co.,  London,  the  Cutter  Laboratory, 
Berkeley,  California,  the  Lederle  Laboratory,  New  York, 
Mulford  &  Co.,  Philadelphia,  Parke,  Davis  &  Co.  and 
Stearns  &  Co. ,  Detroit.     These  are  all  polyvalent  sera. 

The  studies  of  Michaelis  and  of  Aronson  indicate  that 
the  antistreptococcus  sera  are  not  bactericidal  in  their 
action,  since  streptococci  grow  almost  equally  well  in 
normal  and  immune  serum.  The  conclusions  reached  by 
these  two  investigators  are  that  the  immune  serum  sup- 
plies the  specific  opsonin  which  prepares  the  streptococci 
for  ingestion  by  the  phagocytes. 

The  Antituberculosis  Serum  of  Marmorek. — Wohlberg^ 
treated  16  cases  of  tuberculosis  with  Marmorek' s  serum, 
and  reaches  the  conclusion  that  the  serum  is  of  great 
value  in  the  treatment  of  scrofulosis.  In  fully  developed 
cases  of  tuberculosis  the  serum  did  not  seem  to  be  of 
definite  service. 

An  antitubercle  serum  is  also  prepared  by  Parke,  Davis 
&  Co.,  Detroit.  This  is  prepared  by  treating  horses  for 
several  months  with  the  toxic  products  of  the  tubercle 
germs. 

Antimeningococcus  5erum. — Flexner  in  America  and 
Jochmann  in  Germany  have  prepared  an  antiserum  for 
the   treatment   of  cerebrospinal   meningitis.      Flexner's 

'^Berliner  Uinische  Wochenschrift,  November  18,  1907,  p.  i486. 


372  VITAL   CAUSES  OF  DISEASE. 

serum  has  been  employed  in  a  number  of  cases  of  cerebro- 
spinal fever  in  various  stages  of  the  disease,  and  the  re- 
sults appear  to  indicate  the  curative  value  of  the  serum, 
though  the  question  may  be  said  to  be  still  under  inves- 
tigation, as  it  will  require  a  large  series  of  cases  to  estab- 
lish its  relative  value. 

Antimeningococcus  serum  is  prepared  by  Meister, 
Lucius  and  Bruening,  Hochst  A.  M.,  Germany,  and  by 
H.  K.  Mulford  Co.,  Philadelphia.  This  serum  is  em- 
ployed for  prophylactic  and  curative  purposes. 

Serum  Therapy  and  Serum  Prophylaxis  in  Acute  Infec° 
tious  Diseases. — W.  Kolle,^  in  a  clinical  lecture,  speaks 
of  the  diphtheria  and  tetanus  sera,  which  contain  the 
antitoxins  discovered  by  von  Behring  ;  he  states  that  the 
employment  of  diphtheria  antitoxin  is  still  at  times 
attended  with  failure,  which  is  partly  due  to  mixed  infec- 
tions, and  partly  due  to  disease  of  important  organs,  as 
the  heart  and  kidneys,  and  in  part  to  unknown  causes. 
He  believes  that  the  latter  source  of  failure  may  be  elimi- 
nated by  the  employment  of  a  serum  which  possesses,  aside 
from  its  antitoxic  powers,  also  agglutinative  and  bacteri- 
cidal powers.  With  the  tetanus  serum  the  protective 
action  is  far  greater  than  the  curative  power.  The  cura- 
tive power  is  uncertain,  and  can  only  be  expected  with 
certainty  when  the  serum  is  employed  a  short  time  after 
infection.  The  failure  of  the  serum  to  relieve  after 
development  of  the  disease  is  attributed  to  the  fact  that 
before  the  appearance  of  the  nervous  symptoms  the  cells 
of  the  central  nervous  system  and  of  the  nerve-tracts  have 
combined  with  the  tetanus  poison  and  hence  the  antitoxin 
circulating  in  the  blood-stream  remains  without  effect. 

In  typhoid  fever  and  cholera  the  anti-infectious  forms 
of  serum  which  have  been  prepared  against  the  endo- 
toxins contained  in  the  bodies  of  the  bacteria  are  more 
promising  than  the  antitoxic  sera.  The  immune  sub- 
stances contained  in  these  sera  consist  of  bacteriolysins, 
agglutinins,  precipitins,  and  opsonins. 

^Deutsche  med.  Wochenschrift,  1907,  pi  621. 


PRE  VENTION  OF  INFECTION  B  Y  IMMUNITY.     373 

In  the  treatment  of  dysentery  antitoxic  as  well  as  bac- 
tericidal sera  have  shown  themselves  to  be  practical, 
and  Kolle  recommends  the  use  of  both  simultaneously. 

With  regard  to  antistreptococcus  serum,  many  favor- 
able results  as  well  as  many  unfavorable  results  have  been 
reported.  There  is  no  antitoxic  action,  and  we  have  as 
yet  no  knowledge  of  a  soluble  streptococcus  poison.  Kolle 
is  inclined  to  believe  that  the  polyvalent  is  preferable  to 
the  monovalent  serum. 

On  the  other  hand,  the  polyvalent  plague  serum  has 
not  shown  itself  to  be  superior  to  the  monovalent  serum. 
Antiplague  serum  produces  a  passive  immunity,  and  is, 
therefore,  a  reliable  protective,  but  one  cannot  rely  upon 
its  curative  action.  Its  value  can  be  easily  determined 
by  experiments  upon  rats.  In  the  test-tube  no  distinct 
bactericidal  action  is  to  be  demonstrated,  as  is  the  case 
with  cholera  and  typhoid  sera. 

The  meningococcus  serum  exerts  no  antitoxic  action, 
and  its  value  is  very  difficult  to  measure  because  we  have 
no  susceptible  animals  upon  which  to  test  it.  Kolle  and 
Wassermann  have  perfected  a  procedure  in  which  specific 
substances  in  this  serum  can  be  demonstrated  through 
complement  deviation.  As  to  its  curative  value,  no  defi- 
nite conclusion  is  possible  at  this  time.  Its  employment 
in  the  very  beginning  of  the  disease  will  make  success 
more  probable. 

Prevention  of  Infection  by  Inducing  Active  Im- 
munity.— An  enormous  amount  of  work  has  been  per- 
formed to  discover  methods  of  preventing  the  action  of 
pathogenic  bacteria  by  means  of  their  metabolic  products. 

The  use  of  the  metabolic  products  of  the  tubercle 
bacillus,  the  tuberculin  of  Koch,  in  the  treatment  of 
tuberculosis  was  not  attended  by  the  favorable  results  at 
first  expected.  This  agent  is,  however,  of  great  value  as 
a  diagnostic  agent  for  the  discovery  of  the  presence  of 
the  disease  in  the  early  stages  in  man  and  animals.  In 
this  manner  it  becomes  a  most  important  preventive 
agent  by  the  early  discovery  of  the  disease  in  cattle,  thus 


374  VITAL   CAUSES  OF  DISEASE. 

limiting  the  danger  of  the  dissemination  of  the  disease 
through  infected  meat,  milk,  and  milk  products. 

The  determination  of  the  relative  susceptibility  of  in- 
dividuals to  diphtheria  infection  by  the  injection  of  a 
mixture  of  diphtheria  toxin  and  antitoxin  has  recently 
come  into  general  use  in  New  York  City  as  well  as  in 
Europe.  The  same  mixture  may  also  be  employed  in 
producing  an  active  immunity  in  a  much  shorter  time 
and  of  a  higher  grade  than  with  antitoxin  alone. 

The  valuable  results  obtained  in  the  prophylactic  treat- 
ment of  cattle  with  anthrax  vaccine — an  attenuated  cult- 
ure of  the  anthrax  bacillus ;  the  important  work  of 
Pearson  and  Gilliland  in  the  vaccination  of  cattle  against 
tuberculosis  ;  the  prophylactic  treatment  of  cattle  with 
blackleg  virus — a  highly  attenuated  culture  of  the  black- 
leg bacillus,  as  well  as  other  animal  diseases  which  are 
treated  or  prevented  by  antitoxin  ;  the  great  value  of  ac- 
tive immunization  of  human  beings  against  cholera,  ty- 
phoid fever,  and  dysentery  by  injections  of  dead  organ- 
isms ;  and  the  value  of  the  prophylactic  measures  against 
small-pox  and  diphtheria  as  practised  in  the  human 
family,  lead  us  to  hope  that  other  prophylactic  agents 
may  be  discovered  to  combat  the  development  of  infec- 
tious diseases. 

The  Haffkine  Method  of  Protection.— The  Hafifkine 
method  of  protection  against  typhoid  fever,  cholera, 
and  bubonic  plague  by  means  of  heated  cultures  of  the 
respective  organisms  has  been  found  of  great  value.  The 
protection  of  English  soldiers  and  army  nurses  against 
typhoid  fever  by  the  injection  of  killed  cultures  appears 
to  have  been  of  signal  benefit  during  the  past  few  years. 
It  has  been  the  experience  of  English  army  surgeons  in 
South  Africa  that,  where  heretofore  nurses  in  the  army  hos- 
pitals frequently  contracted  typhoid  fever  from  patients, 
since  the  introduction  of  this  method  of  protection  the 
danger  of  infection  of  nurses  has  been  practically  elimi- 
nated. The  experience  in  the  German  army  serving  in 
South  Africa  has  been  found  to  be  equally  satisfactory. 


PRE  VENTION  OF  INFECTION  B  V  IMMUNITY.     375 

The  same  method  has  been  employed  in  the  protection 
of  the  soldiers  in  the  United  States  army  with  very  satis- 
factory results.  In  a  similar  manner  dead  cultures  of 
the  cholera  organism  are  being  emplo}-ed  to  protect  indi- 
viduals against  cholera,  dead  dysentery  bacilli  to  protect 
against  dysentery,  and  dead  plague  cultures  to  protect 
against  plague.  Usually  bouillon  cultures  are  employed 
that  have  been  killed  by  subjecting  them  to  heat.  Such 
heated  cultures  have  been  designated  Haff  kine  fluids,  as 
they  were  first  proposed  by  Haffkine. 

The  prophylactic  agents  employed  act  in  different  ways. 
The  anthrax  and  blackleg  viruses  act  by  inducing  a  mild 
type  of  the  disease,  and  in  this  manner  confer  immunity. 
The  metabolic  products  of  the  bacteria  when  injected 
into  an  animal  also  cause  the  formation  of  specific  anti- 
bodies in  the  blood  of  the  animal,  and  thus  renders  it 
immune.  The  use  of  dead  cultures,  as  in  the  Haffkine 
method  and  in  the  Wright  method,  confers  an  active  im- 
munity against  the  disease  which  lasts  for  a  }-ear  or 
longer. 

With  the  view  of  overcoming  the  disadvantages  of  the 
Haffkine  injections,  Besredka^  injected  a  culture  of  an 
organism  which  had  been  treated  with  the  specific  ambo- 
ceptors for  that  organism.  It  will  be  recalled  that  ambo- 
ceptors are  the  intermediary  bodies  that  bind  the  com- 
plement to  the  bacilli.  The  amboceptors  resist  heat, 
low  degrees  of  which  (56°  C.)  remove  complement.  For 
example,  a  culture  of  the  typhoid  bacillus  was  suspended 
in  salt  solution  and  enough  heated  antityphoid  serum 
added  to  cause  complete  agglutination.  The  mixture 
was  allowed  to  stand  for  six  hours,  during  which  time 
the  bacteriolytic  amboceptors,  as  well  as  the  agglutinat- 
ing bodies,  are  fixed  to  the  bacteria.  The  bacteria  were 
then  washed  free  of  serum  by  repeated  centrifugating  in 
salt  solution.  The  sediment,  consisting  of  typhoid  ba- 
cilli plus  the  immune  bodies,  was  then  injected  into 
animals.  It  was  found  that  immediate  immunity  was 
^  Besredka,  Ann.  de  I'Inst.  Past.,  1902,  vol.  xvi.,  p.  918. 


17^  VITAL    CAUSES  OF  DISEASE. 

conferred,  which  endured  for  at  least  five  or  six  months. 
No  general  or  local  symptoms  followed  the  injection  ; 
and  this  was  true  of  an  injection  Besredka  made  in  him- 
self. The  same  experiments  were  made  with  cholera 
and  plague  ;  in  working  with  the  latter  killed  organisms 
were  used. 

Protective  Immunization  Against  Plague. — W.  KoUe 
and  Richard  P.  Strong^  experimented  with  a  lowly  viru- 
lent plague  culture  which  had  been  cultivated  four  months 
at  41°  to  43°  C,  so  that  it  had  become  attenuated  to  such  a 
degree  that  guinea-pigs  and  rats,  which  are  very  suscep- 
tible to  plague,  could  withstand  a  millionfold  the  quantity 
of  culture.  It  was  shown  by  inoculations  of  forty-two 
human  beings  that  this  vaccine  is  without  detrimental 
effect  other  than  a  slight  fever  and  a  slight  local  reaction, 
both  of  which  disappeared  within  three  days  in  29  of  these 
individuals.  The  blood  was  examined  as  to  its  aggluti- 
nating power  as  well  as  for  its  protective  power  when 
administered  to  animals,  and  was  found  to  agglutinate 
fresh  plague  cultures  as  well  as  to  protect  animals  against 
inoculations  of  plague  cultures. 

Prophylactic  Immunization  Against  Cholera. — Leon 
Karwacki^  inoculated  himself  and  ten  other  persons  with 
cholera  vaccine.  At  the  first  ■  inoculation  he  employed 
one  cubic  centimeter,  and  at  the  second  inoculation,  made 
five  days  later,  he  employed  two  cubic  centimeters,  injected 
under  the  skin  of  the  arm.  The  effects  of  the  inoculations 
were  reddening  and  swelling  at  the  point  of  inoculation, 
and  in  some  of  the  individuals  swelling  of  the  axillary  lym- 
phatics, a  slight  rise  in  temperature,  never  reaching  38°  C, 
a  slight  general  indisposition,  and  headache.  After  the 
second  inoculation  the  reddening  of  the  skin  at  the  point  of 
inoculation  was  the  only  effect  noticed.  Blood  was  drawn 
from  these  eleven  persons  before  inoculation,  five  days 
after  the  first  inoculation,  and  ten  days  after  the  second 
inoculation,    and    tested    in   regard    to   its    bacteriolytic 

^  Deutsche  med.  Wochenschrift,  1906,  p.  413. 
^  Zeitschr.  f.  Hyg.,  Bd.  liv.,  p.  39. 


IMMUNIZATION  AGAINST  TYPHOID  FEVER.  377 

power.  While  the  blood  before  the  inoculation  in  its 
undiluted  state  in  about  half  the  tests  gave  a  satis- 
factory Pfeijffer  reaction,  after  the  first  inoculation  the  tests 
showed  an  average  of  fifty  bacteriolytic  units,  and  after  the 
second  inoculation  it  rose  to  5000  to  10,000  units,  In  three 
convalescents  from  cholera  the  bacteriolytic  power  of  one 
was  of  1000  units  and  of  the  other  two,  5000  units.  The 
same  increase  in  the  agglutinating  power  was  noted  in  the 
blood  as  the  result  of  the  inoculations.  After  the  second 
inoculation  the  antibody  formation  reached  about  the 
height  of  that  found  in  individuals  who  had  recovered 
from  cholera. 

S.  Serkowski  ^  made  altogether  353  prophylactic  inocu- 
lations against  cholera.  Besides  the  Kolle  method,  he 
employed  in  7  cases  the  Neisser-Shiga  method.  There 
was  no  diflference  in  the  results  obtained  by  the  two  meth- 
ods, but  there  was  a  decided  preference  for  the  Kolle 
method  because  of  the  simplicity  of  the  technique.  In 
forty-one  individuals  he  determined  the  bacteriolytic 
power  of  the  blood  before  the  first  inoculation,  and  five 
days  after  the  second  and  third  inoculations.  He  was  able 
to  note  a  definite  increase  in  the  bacteriolytic  power  cor- 
responding with  the  size  of  the  doses  injected  and  the 
number  of  injections.  But  there  was  not  a  similar  relation 
between  the  dose  of  the  vaccine  and  the  agglutinative 
power  of  the  blood.  Repeated  inoculations  increase  the 
degree  of  immunity  as  well  as  its  permanency,  and  he 
concludes  with  Kolle  that  injections  of  the  largest  pos- 
sible doses  of  dead  cultures  give  the  best  and  most  per- 
manent results. 

Protective  Immunization  Against  Tj'phoid  Fever. — No 
hygienic  measure  discovered  in  modern  times  compares 
in  value  with  the  beneficial  effects  which  result  from  the 
prophylactic  inoculation  of  soldiers  against  typhoid  fever. 
During  the  Spanish- American  War,  out  of  a  total 
strength  of  107,973  men,  there  were  20,738  cases  of  ty- 

^  Centralblat.  f.  Bakt.,  Bd.,  xli.,  p.  255. 


378  VITAL  CAUSES  OF  DISEASE. 

phoid  fever  and  1580  deaths,  representing  86.24  per  cent, 
of  the  entire  mortahty  of  the  war.^ 

The  commander  of  the  German  troops  sent  to  South 
i\frica  makes  the  following  report  upon  two  incidents  as 
to  the  influence  of  these  inoculations  and  the  mortality 
of  typhoid  feyer.-  Four  hundred  and  twenty-four  cases 
of  typhoid  feyer  came  under  obseryation,  of  which  100 
had  been  inoculated.  The  mortality  among  the  latter 
was  4  per  cent.,  while  among  the  uninoculated  it  was 
II. I  percent.  In  the  inoculated  the  disease  pursued  a 
lighter  course ;  the  intoxication,  as  indicated  by  head- 
ache, disturbances  of  the  sensorium,  and  the  heart  action, 
is  slight,  the  complications  fewer,  and  the  relapses  less 
frequent. 

Note. — For  further  information  concerning  the  appli- 
cation of  antityphoid  vaccination  in  the  army  and  navy, 
see  p.  320. 

Prophylactic  immunization  against  paratyphoid  fever 
and  dysentery  has  proved  just  as  efficacious  as  anti- 
typhoid vaccination.  This  mode  of  protection  against 
dysentery  is  of  especial  value  in  asylums  and  institutions 
where  large  numbers  of  persons  are  maintained  in  rather 
close  confinement. 

Active  Immunization  Against  Diphtheria. — In  insti- 
tutions where  a  number  of  childern  are  associated 
those  that  are  susceptible  to  diphtheria  infection  may  be 
detected  by  the  Schick  reaction,  that  is,  by  the  intra- 
dermic  administration  of  h  M.  L.  D.  of  diphtheria  toxin. 
Those  that  give  a  positive  reaction  should  be  immunized 
by  the  administration  of  a  mixture  of  diphtheria  toxin 
and  antitoxin.  In  this  way  an  active  immunity  is 
induced. 

Protective  Immunization  Against  Whooping=cough. 
— Protective  immunization  against  whooping-cough 
has     been     tried     quite     extensively    in     New     York 

^  Russell,  House  of  Representatives,  Sixty-first  Congress,  Third  Session, 
Document  No.  1445,  Washington,  1911. 

-  Arch.  f.  Schifs-  u.  Tropenhyg.,  Bd.  ix.,  p.  527. 


VALUE  OF  VACCINATION.  379 

City,  using  killed  cultures  of  Bacillus  pertussis.  Dr. 
Shaw,  Director  of  Division  of  Child  Hygiene,  New  York 
State  Department  of  Health  ("Health  News,"  March, 
19 1 7),  says:  "The  value  of  the  vaccines  as  a  prophylactic 
measure  is  undeniable,  and  they  should  be  administered 
to  every  child  exposed  to  whooping-cough."  Although 
not  every  child  that  is  immunized  is  protected  against 
the  disease,  yet  the  proportion  that  develop  the  disease 
is  quite  low,  only  4  per  cent,  of  those  treated  with  vac- 
cines prepared  by  the  New  York  City  Health  Labor- 
atories developed  the  disease.  Because  of  the  unsatis- 
factory results  of  the  treatment  of  the  disease  the  rel- 
atively -  high  mortality  and  the  predisposition  of  an 
attack  of  whooping-cough  to  other  diseases  are  impor- 
tant reasons  for  recommending  the  vaccines. 

Protective  Vaccination  of  Cattle  Against  Tuberculosis. — 
F.  Hutyra^  tested  von  Behring's  method  of  vaccinating 
cattle,  and  the  results  obtained  led  to  a  quite  optimistic 
expression  of  belief  in  the  permanent  value  of  this  method, 
but  later  experiments  have  caused  him  to  speak  of  the 
method  with  greater  reserve.  It  appears  that  the  resist- 
ance conferred  by  von  Behring's  method  against  subse- 
quent intravenous  injection  with  tubercle  bacilli  declines 
quite  rapidly  and  disappears  entirely  toward  the  end  of 
the  first  year.  The  resistance  of  inoculated  cattle  toward 
natural  infection  from  other  tuberculous  cattle  is  never 
striking  and  disappears  after  a  few  months. 

In  further  experiments  to  test  von  Behring's  method 
two  intravenous  vaccinations  were  given  in  the  place  of 
one,  as  previously  recommended.  It  was  found  that  the 
resisting  power  of  cattle  thus  treated  was  at  first  very  pro- 
nounced or  almost  absolute,  but  that  it  was  not  of  long 
duration,  disappearing  entirely  within  eighteen  months. 
Hutyra  concludes  from  his  experiments  that  at  present 
the  only  method  for  controlling  tuberculosis  which  has 
stood  practical  test  is  that  of  Bang. 

Value    of   Vaccination  as  a  Protective    against 

']}  Ztchr.f.  Tuberkulose,  1997,  pp.  97-122. 


38o 


VITAL  CAUSES  OF  DISEASE. 


Small-pox. — Vaccination  is  the  only  preventive  against 
small-pox.  This  has  been  demonstrated  by  the  experi- 
ence in  countries  where  compulsory  vaccination  is  in 
force,  as  well  as  in  the  experience  of  employees  of  small- 
pox hospitals.  A  single  vaccination  in  infancy  is  usu- 
ally not  sufficient  to  protect  against  small-pox  during 
life.  Revaccination  should  be  required  at  stated  inter- 
vals, every  five  or  seven  years,  where  no  small-pox  exists. 
Whenever  there  is  an  outbreak  in  the  community,  all 
persons  should  be  vaccinated  at  once  and  the  revaccina- 
tion continued  as  long  as  there  is  any  reaction  to  the 
vaccine.  Repeated  vaccination  until  there  is  no  longer 
any  reaction  is  believed  to  be  absolutely  protective 
against  small-pox.  This  is  the  only  protection  em- 
ployed for  physicians,  nurses,  and  undertakers  who 
come  in  daily  contact  with  small-pox  patients.  It  has 
been  found  that  this  form  of  protection  is  even  more 
effective  than  a  previous  attack  of  small-pox,  especially 
if  some  years  have  elapsed  since  the  attack. 

Erismann '  states  that  in  Prussia  at  the  beginning  of 
the  nineteenth  century,  before  vaccination  became  gen- 
eral, there  were  2000  to  3000  deaths  from  small-pox 
annually.  After  vaccination  was  made  compulsory  the 
death-rate  from  small-pox  was  reduced  to  200  per 
1,000,000  inhabitants  per  year  ;  and  since  the  law  of 
1874,  requiring  re-vaccination  in  schools  and  the  army, 
the  disease  is  still  rarer.  In  1894  there  were  88,  in  1895 
there  were  27,  and  in  1896  there  were  10  deaths  from 
small-pox.  The  results  in  neighboring  countries  are  as 
follows: 


Number  of  deaths  in 

1893. 

1894. 

1895. 

1896. 

Austria 

Hungary     .... 

Italy 

France     

5821 
1224 

8002 

837 

859 

1937 
2998 

865 
2039 

^  Abst.,  Centralhlatt.  f.  Bacteriologie,  Bd.  xxviii.,  S.  617.        ^  Estimated. 


VALUE  OF  VACCINATION.  381 

Finkelburg  ^  discusses  the  dangers  from  vaccination  by 
means  of  bovine  lymph,  and  states  that  the  practical 
experiences  of  vaccine  physicians  teach  that  the  regula- 
tions for  the  production  of  the  lymph  are  not  altogether 
satisfactory  from  a  sanitary  standpoint,  and  advises 
"  (i)  the  introduction  of  a  simple  method  of  disinfection 
of  the  vaccination  field  and  of  the  instruments  ;  and  (2) 
obligatory  direction  of  the  use  of  a  protective  bandage, 
which  is  applied  at  once  and  remains  in  position  until 
the  pustule  has  healed." 

According  to  Haase,^  when  the  vaccination  field  is  not 
washed,  31.45  per  cent,  of  the  vaccinations  present 
marked  reaction;  washing  with  soap  and  water  reduces 
the  number  to  22.63  per  cent.;  while  after  disinfection 
with  alcohol,  or  water,  soap,  and  alcohol,  none  of  the 
cases  showed  marked  reaction.  No  protective  bandage 
was  employed. 

Schoen^  reports  on  small-pox  among  the  native  black 
races  of  Africa.  The  disease  is  generally  distributed 
along  the  upper  tributaries  of  the  Nile  in  Nubia,  Cordova, 
Abyssinia,  Soudan,  and  along  the  eastern  coast.  In 
Western  Africa  the  disease  is  less  generally  distributed 
because  there  is  less  intercourse  with  the  central  portion 
of  Africa  and  with  Asia.  At  times,  however,  the  disease 
is  introduced,  and  large  epidemics  and  pandemics  result, 
extending  over  entire  districts  and  tribes.  In  Bogamayo 
(East  Africa)  nearly  all  the  natives  are  pock-marked.  In 
1892,  Salaam  lost  10  per  cent,  of  its  inhabitants  from 
small-pox.  In  the  southern  portion  of  East  Soudan  an 
epidemic  destroyed  600  out  of  1400  members  of  a  tribe 
and  5  per  cent,  of  the  total  population.  According  to 
Steiidel,  about  one-half  of  the  natives  die  of  small-pox  in 
Central  Africa.  According  to  Becker,  most  of  the  natives 
of  German  Africa  who  reach  the  age  of  manhood  have 

1  Centralblatt  f.  allgemeine  Gesundheitspjlege,  Ed.  xviii,  S.  357. 

^  Zeitschrift  f.  Aledizinalbeatnie,  1 899. 

3  Centralblatt  f.  Bacteriologie,  vol.  xx.,  p.  64I. 


382  VITAL  CAUSES  OF  DISEASE. 

had  the  disease.     Compulsory  vaccination  is  the  only 
remedy,  according  to  Schoen. 

The  extremely  low  death-rate  from  small-pox  in  Ger- 
many indicates  the  importance  of  re-vaccinations  at  stated 
intervals.  It  is  also  evident  from  observations  in  England 
and  America  that  both  the  incidence  and  the  mortality 
of  the  disease  are  directly  proportional  to  the  protection 
afforded  by  vaccination  as  indicated  by  the  number  and 
distinctness  of  the  vaccination  marks. 

Dr.  William  M.  Welch,  of  the  Municipal  Hospital  for 
Contagious  and  Infectious  Diseases,  Philadelphia,^  states 
that  "in  every  epidemic  of  small-pox  that  has  occurred 
in  Philadelphia  within  the  past  thirty  years,  instances 
have  been  observed  of  whole  families  having  removed 
to  the  hospital  because  of  an  outbreak  of  the  disease 
(small-pox)  in  these  families.  In  such  instances  the 
unvaccinated  children  have  suffered  and  often  perished, 
while  those  who  were  vaccinated  remained  perfectly 
exempt,  although  living,  eating,  and  sleeping  in  the 
infected  atmosphere  for  several  weeks.  But  I  have  yet 
to  see  a  single  unvaccinated  child  escape  the  disease 
under  similar  conditions  of  exposure.  Furthermore,  I 
have  more  than  once  seen  a  vaccinated  infant  take  its 
daily  supply  of  nourishment  from  the  breast  of  its 
mother  who  was  suffering  from  varioloid,  and  the  infant 
continue  as  free  from  small-pox  as  if  the  disease  were 
a  hundred  miles  away,  and  the  food  derived  from  the 
most  wholesome  source.  This  is  evidence  of  the  pro- 
phylactic power  of  vaccination  that  does  not  appear  in 
mortality  reports  nor  in. statistical  records. 

"  Not  many  weeks  since  a  pregnant  woman  nearly  at 
term  was  admitted  with  varioloid.  In  the  course  of  the 
disease  labor  occurred,  and  a  male  child  weighing  8^ 
pounds  was  born.  About  five  hours  after  its  birth  the 
infant  was  vaccinated,  two  insertions  being  made. 
Again,   two    days     subsequently,   two    more    insertions 

^American  Medicine,  1902,  vol.  iv. 


PRECAUTIONS  IN  VACCINATION.  383 

were  made.  Four  large  vaccine  vesicles  developed, 
causing  a  very  sore  arm,  but  did  not  give  rise  to  any 
considerable  elevation  of  temperature  nor  to  any  appar- 
ent disturbance  of  the  health  of  the  infant.  After  re- 
maining in  the  hospital  thirty-two  days  and  proving  its 
newly  acquired  immunity  to  small-pox  in  a  most  indu- 
bitable manner,  the  infant  was  taken  home  by  its  mother, 
who  had  made  a  good  recovery  without  untoward  symp- 
toms. ' ' 

Precautions  in  Vaccination. — More  or  less  objection 
to  vaccination  is  encountered  in  some  communities. 
This  objection  may  be  divided  into  several  different 
classes  :  (i)  That  of  the  anti-vaccinationists,  which  it  is 
not  necessary  to  consider  here.  (2)  That  of  those  who 
fear  the  transmission  of  some  disease  in  the  vaccine. 
This  objection  is  groundless  at  the  present  day,  since  all 
the  vaccine  on  the  market  is  of  bovine  origin.  It  is 
doubtful  whether  any  cases  of  tetanus  following  vacci- 
nation have  been  certainly  traced  to  the  vaccine  virus. 
(3)  That  of  those  who  fear  the  development  of  very  sore 
arms  with  danger  of  blood-poisoning.  This  danger  is 
largely  due  to  the  ignorance  and  neglect  of  the  vacci- 
nated. In  order  to  avoid  unnecessary  discomfort  in  this 
respect,  the  operation  should  be  conducted  under  aseptic 
precautions  and  the  vaccinated  wound  properly  pro- 
tected. The  arm  should  be  first  thoroughly  washed 
with  soap  and  water  and  the  site  of  the  operation  then 
washed  with  alcohol.  After  the  vaccination  is  made 
the  site  should  be  protected  from  rubbing  by  means  of 
a  piece  of  clean  soft  muslin  pinned  to  the  undershirt. 
This  should  be  changed  each  day  until  the  scab  falls 
off.  It  is  probable  that  this  procedure  is  far  preferable 
to  the  use  of  the  different  forms  of  shields  which  have 
been  placed  on  the  market  in  recent  years.  Great  care 
must  be  exercised  to  prevent  the  rupture  of  the  vesicle 
or  the  premature  removal  of  the  scab.      Should  either 


384  VITAL  CAUSES  OF  DISEASE. 

of  these  contingencies  occur,  the  vaccination  should  be 
treated  like  any  other  open  wound. 

The  vaccination  operation  consists  in  exposing  the 
true  skin  by  removing  the  cuticle  by  means  of  a  blunt 
sterilized  needle.  No  blood  should  be  drawn  in  the 
operation.  The  exposed  area  should  not  exceed  five 
millimeters  in  diameter  (one-fourth  of  an  inch). 

Biologic  Aids  to  Diagnosis. — The  importance  of  the 
early  diagnosis  of  transmissible  diseases  cannot  be  too 
strongly  emphasized,  and  we  must  welcome,  therefore, 
everything  that  will  render  an  early  diagnosis  more  cer- 
tain. In  addition  to  the  direct  bacteriological  examina- 
tions, as  applied  to  the  diagnosis  of  diphtheria,  tubercu- 
losis, gonorrhea,  cerebrospinal  meningitis,  and  other 
diseases,  we  have  for  a  number  of  years  employed  the 
agglutination  reaction  for  the  early  diagnosis  of  typhoid 
fever,  and  the  tuberculin  test  for  the  detection  of  tubercu- 
losis. During  recent  years  we  have  added  several  im- 
portant additional  aids  to  diagnosis  and  to  our  manage- 
ment of  transmissible  diseases. 

Von  Pirquet  called  attention,  on  May  8,  1907,  to  the 
fact  that  tuberculosis  can  be  diagnosed  in  children  by  the 
introduction,  into  cutaneous  scarifications,  of  25  per  cent, 
tuberculin,  the  reaction  being  the  formation  of  a  typical 
papule  at  the  point  of  instillation  in  those  that  are  tubercu- 
lar, while  no  reaction  is  seen  in  non-tubercular  persons. 
A  week  later  Wolff-Eisner  reported  that  a  similar  reaction 
could  be  obtained  by  the  instillation  of  10  per  cent,  tuber- 
culin into  the  conjunctival  sac.  Calmette  has  since  advised 
the  use  of  a  i  per  cent,  tuberculin  for  the  eye  reaction. 

Chantemesse^  reports  on  an  ophthalmo-diagnostic  test 
in  typhoid  fever,  which  consists  of  the  instillation,  into 
the  conjunctival  sac,  of  Y^  mg.  of  a  dry  powder  obtained 
from  typhoid  bacilli,  suspended  in  a  drop  of  water,  which 
calls  forth  a  reaction  in  those  suffering  from  typhoid  fever, 
while  it  is  without  effect  in  healthy  individuals.     He 

'^Deutsche  med.  W ochenschrift,  1907,  p.  1572. 


BIOLOGIC  AIDS  TO  DIAGNOSIS.  385 

found  this  ophthalmic  reaction  to  antedate  the  aggluti- 
nation reaction  by  several  days.  In  70  typhoid  patients 
the  reaction  was  positive  in  each  instance,  while  it  was 
negative  in  50  non-typhoid  individuals. 

Deehan^  has  perfected  an  extract  from  the  typhoid  ba- 
cillus which,  in  his  hands,  served  to  diagnose  typhoid 
fever  when  employed  in  cutaneous  scarifications. 

Martel  ^  has  demonstrated  that  the  von  Pirquet  cutane- 
ous reaction,  as  well  as  the  ophthalmic  reaction,  can  be 
successfully  produced  with  mallein  in  individuals  who 
suffer  from  glanders.  In  every  individual  suffering  from 
oflanders  that  was  tested  there  was  a  definite  reaction, 
while  there  was  no  effect  in  healthy  individuals.  Mallein 
was  used  in  i  :  10  to  i  :  4  dilution  for  the  cutaneous  test, 
and  in  i  :  60  dilution  for  the  ophthalmic  test. 

The  Shick  method  of  determining  the  degree  of  sus- 
ceptibility to  diphtheria  infection  by  the  intradermal  in- 
jection of  a  mixture  of  diphtheria  toxin  and  antitoxin 
has  been  found  very  valuable  by  Dr.  Park,  of  New  York 
City. 

Wassermann,  Neisser,  and  Bruck^  have  proposed  a 
serum  diagnostic  test  for  syphilis  which  is  based  upon  the 
complement  binding  method  of  Bordet  and  Gengou.  They 
^ound  that  the  serum  of  monkeys  that  had  been  treated 
with  syphilitic  material  after  a  time  acquired  the  prop- 
erty of  binding  complement  when  brought  in  relation 
with  extracts  of  syphilitic  materials.  If  now  there  are 
added  a  heated  hemolytic  serum  and  blood-corpuscles,  no 
hemolysis  takes  place,  since  the  complement  has  been 
combined  with  an  antibody  in  the  syphilitic  extract. 

Michaelis^  has  found  that  it  is  possible  to  diagnose  the 
presence  of  syphilis  by  means  of  a  precipitation  reaction 

1  Univ.  of  Penna.  Med.  Mag.,  1909. 
^Berliner  klin.  Wochenschrift,  Bd.  xlv.,  p.  451. 
3  Deutsche  med.  Wochenschrift,  1906,  p.  745. 

*  Berliner  klin.  Wochenschrift,  Bd.  xlvi.,  p.  1477,  November  18, 
1907. 

.25 


386  VITAL  CAUSES  OF  DISEASE. 

when  syphilitic  serum  and  syphilitic  liver  extract  are 
mixed  in  certain  definite  proportions.  The  precipitation 
reaction  is  not  produced  with  normal  serum  and  syphilitic 
liver  extract,  nor  with  syphilitic  serum  and  normal  liver 
extract. 

Personal  Prophylaxis. — In  treating  cases  of  infec- 
tious diseases,  it  is  inadvisable  for  the  physician  to  wear 
specially  constructed  suits  for  his  protection  against  in- 
fection. There  are,  however,  a  number  of  precautionary 
measures  that  should  be  taken.  The  physician  may 
wear  a  linen  duster  or  operating-coat  over  his  clothing 
while  in  the  sick-room,  since  this  will  not  be  so  likely 
to  alarm  the  patient,  and  will  serve  in  a  large  measure  to 
keep  infective  materials  from  his  own  clothing.  This 
coat  should  be  left  in  an  ante-room  or  just  outside  the 
door  of  the  sick-room,  and  should  be  disinfected  after 
each  visit  in  such  diseases  as  small-pox  and  scarlet  fever. 
He  should  time  his  visits  so  as  to  have  a  full  stomach, 
and  should  spend  as  much  time  as  possible  in  the  open 
air  subsequently.  He  should  secure  at  least  eight  hours 
of  sleep,  so  as  to  maintain  his  physical  vigor.  He  should 
abstain  from  the  use  of  alcoholic  beverages.  Personal 
cleanliness  is  of  the  greatest  importance,  and  daily  baths 
are  to  be  recommended.  Great  care  should  be  taken  in 
keeping  the  hands  and  nails  scrupulously  clean,  and  it  is 
advisable  for  the  physician  to  wash  his  hands  imme- 
diately after  handling  the  patient.  There  is  no  doubt 
that  many  physicians  have  lost  their  lives  in  consequence 
of  neglect  of  this  point.  This  is  especially  true  of 
typhoid  fever,  where  the  patient's  body  and  clothing  are 
soiled  by  fecal  matter  and  urine.  The  same  precautions 
apply  with  equal,  or  even  greater,  force  to  the  nurse. 
Drugs  have  no  influence  whatever  in  warding  off  disease, 
though  there  is  a  widespread  belief  to  the  contrary  among 
the  laity. 

Physicians  as  Carriers  of  Infection. — Dr.  A.  G.  Young, 
Secretary  of  the  Maine  State  Board  of  Health,  gives  the 


PERSONAL  PROPHYLAXIS.  387 

following  method  practised  by  him  in  rural  districts  to 
prevent  the  carrying  of  infection. 

When  visiting  cases  of  small-pox,  diphtheria,  or  otlier 
infections  diseases,  a  good  method  of  procedure  is  to 
leave  overcoat,  hat,  undercoat,  and  usually  collar  and 
necktie  outside  of  the  house  containing  the  patient.  Call 
for  an  earthenware  washbowl  from  the  house  and  a  quart 
of  hot  water — nothing  else.  From  a  small  and  tightly 
closinof  bag:  take  out  a  bottle  of  bichlorid  tablets,  one  or 
two  of  which  are  dropped  into  the  washbowl  to  be  dis- 
solving while  inside  ;  then  take  out  and  slip  on  a  pair  of 
white  duck  trousers,  then  a  barber's  white  coat  with  an 
extra  button  which  buttons  up  closely  around  the  neck. 
Rubber  bands  around  the  ends  of  the  sleeves  of  the  coat 
and  a  silk  skull-cap  complete  the  attire.  After  leaving 
the  infected  room  soak  the  hands  in  the  bichlorid  solu- 
tion, remove  a  towel  from  the  grip,  a  two-ounce  vial  of 
formaldehyd  solution,  and  two  surgeon's  hand-brushes. 
Then  take  off  the  white  coat  and  trousers,  roll  them  up 
carefully,  and  place  them  in  the  grip  with  the  cap.  Then 
wash  the  hands  again  in  the  disinfecting  solution,  and 
wash  the  wrists,  head,  face,  and  neck,  wetting  the  hair 
thoroughly.  Dipping  the  brushes  in  the  bichlorid  solu- 
tion, scrub  down  the  clothing,  particularly  the  lower  part 
of  the  trousers,  and  finally  the  boots.  Then  all  the  re- 
maining things  are  placed  in  the  grip,  the  towel  on  top. 
Upon  this  towel  pour  an  ounce  or  more  of  formaldehyd 
solution,  and  close  the  grip  immediately.  The  things 
are  disinfected  in  five  or  six  hours.  The  bag  usually 
remains  closed  the  following  night,  and  the  next  morn- 
ing is  opened  and  the  things  are  aired  for  further  use. 

The  following  scheme  is  one  that  is  very  easily  applied 
and  has  been  adopted  by  hundreds  of  physicians  as  at 
once  practical  and  eflfective  : 

After  contact  with  a  contagious  case,  the  cloth- 
ing is  removed  and  hung  in  a  tight  closet,  a  Scher- 
ing  lamp  lighted  and  placed  therein,   and  the  closet- 


388 


VITAL  CAUSES  OF  DISEASE. 


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390  VITAL  CAUSES  OF  DISEASE. 

door  shut.  If  the  closet  is  tight,  the  clothing  hung 
loosely,  and  the  door  kept  closed  while  the  lamp  is 
burning,  five  or  six  hours'  contact  will  give  efficient 
disinfection. 

In  the  preceding  table  an  attempt  has  been  made  to 
present  in  concise  form  the  more  important  points  with 
regard  to  the  direction  in  which  it  is  necessary  to  extend 
our  energies  in  controlling  the  principal  infections  dis- 
eases. Not  all  of  the  preventive  measures  employed  in 
the  different  diseases  are  here  given,  but  only  those  which 
are  deemed  to  be  the  leading  measures.  The  details  with 
regard  to  the  special  modes  of  disinfection  adapted  to 
the  more  important  of  these  diseases  are  given  in  the. 
chapter  on  Disinfection. 

Persistence  of  Pathogenic  Bacteria  in  Dead 
Bodies. — The  possible  danger  of  the  infection  of  the  soil 
and  water  through  pathogenic  bacteria  derived  from  dead 
bodies  after  burial  has  been  frequently  discussed.^  Klein 
has  made  a  practical  investigation  of  the  subject.  He 
inoculated  guinea-pigs  intraperitoneally  with  different 
organisms,  and  after  death  they  were  wrapped  in  cotton, 
placed  in  small  wooden  or  tin  boxes,  or  without  these, 
and  buried  in  moist  earth  or  sand.  When  exhumed,  the 
abdominal  cavity  of  the  animals  was  opened  and  washed 
out  with  I  or  2  cubic  centimeters  of  sterile  salt  solution, 
and  this  fluid  was  used  to  make  cultures.  Bacillus  pro- 
digiosus  and  Staphylococcus  aureus  were  found  alive 
after  twenty-eight  days,  but  had  disappeared  entirely  in 
six  to  eight  weeks.  Cholera  organisms  were  found  alive 
after  nineteen  days,  but  had  disappeared  after  twenty- 
eight  days.  Similar  results  were  obtained  with  typhoid, 
diphtheria,  and  plague  bacilli.  Tubercle  bacilli  died 
during  the  first  seven  weeks.  The  studies  of  Gilder- 
sleeve  ^  show  that  virulent  bacteria,  such  as  Bacillus 
tuberculosis  and  Staphylococcus  pyogenes  aureus,  can  be 

^  Centralbl.  f.  Bacteriologic,  Bd.  xxv.,  S.  727. 
^  Univ.  Penna.  Med.  Bull.,  November,  1901. 


TRANSMISSION  OF  RELAPSING  FEVER.       391 

recovered  from  dead  bodies  in  the  dissecting-room. 
Bodies  preserved  in  strong  brine  or  kept  in  cold  storage 
for  as  lone  as  six  months  still  contained  the  virulent 
bacteria. 

These  results  indicate  that  there  is  danger  of  the  con- 
tamination of  the  soil  and  water  in  the  vicinity  of  ceme- 
teries when  the  bodies  of  those  dying  from  infectious  dis- 
eases are  not  disposed  of  in  a  proper  manner.  The  bodies 
should  be  wrapped  in  sheets  moistened  with  i  :  1000 
bichlorid  of  mercury  solution,  or  5  per  cent,  carbolic 
acid  solution;  all  the  orifices  should  first  be  efficiently 
plugged.  The  bodies  should  be  placed  in  hermeti- 
cally sealed  coffins,  so  that  there  is  no  possibility  for  the 
infectious  material  to  escape.  Cremation  would  be  the 
quickest  and  safest  method  of  disposal  of  the  bodies  of 
persons  dying  of  infectious  diseases,  but  this  mode  of 
disposal  is  objectionable  to  many  persons. 

Transmission  of  Relapsing  Fever. — For  a  long 
time  it  was  believed,  on  the  basis  of  the  investigations 
of  Tictin,  that  the  bedbug  transmitted  relapsing  fever. 
This  assumption  was  not  substantiated  by  animal  experi- 
ments. Mackie^  was  the  first  to  direct  attention  to  the 
role  of  Pediculus  vestimenti  on  the  basis  of  epidemio- 
logical observations  in  an  outbreak  of  relapsing  fever  in 
a  small  school.  On  microscopic  examination  of  clothes 
lice  he  found  14  per  cent,  of  those  secured  from  boys  and 
2.7  per  cent,  of  those  secured  from  girls  to  be  infected 
with  spirochsetes.  Female  lice  were  more  commonly  in- 
fected. The  stomach  and  intestines  contained  spiro- 
chsetes, and  the  fluid  expressed  from  the  mouth  contained 
a  great  many.  He  concluded,  therefore,  that  infection 
occurred  in  the  act  of  sucking  blood.  Sergent  and  Fole}-^ 
showed  that  in  the  Algerian  form  of  relapsing  fever  the 
disease  could  be  transmitted  to  human  beings  and   to 

^  The  Lancet,  1907. 

^  Bull.  Soc.  de  pat  ho.  Exot.,  191 1. 


392  VITAL  CAUSES  OF  DISEASE. 

monkeys  with  crushed  lice  five  to  six  days  after  these  had 
become  infected. 

NicoUe,  Blaizot,  and  Conseil,i  in  Tunis,  showed  that 
Pediculus  vestimenti  as  well  as  Pediculus  capitis  carried 
the  disease.  Five  to  six  hours  after  sucking  blood  the 
spirochsetes  disappeared  from  the  intestines  of  the  lice. 
After  eight  days  the  spirochsetes  reappeared,  and  re- 
mained virulent  until  the  nineteenth  day.  The  percent- 
age of  infective  lice  was  17.57  P^r  cent.  Toyoda-  found 
that  the  spirochsetes  soon  disappeared  from  the  intestine, 
but  about  the  seventh  day  made  their  appearance  in  the 
head  in  the  vicinity  of  glandular  organs,  and  in  conse- 
quence believes  it  is  quite  probable  that  infection  occurs 
in  the  act  of  biting. 

Prevention  of  Malaria. — As  was  shown  by  Smith 
and  Kilborne,  and  substantiated  by  Koch,  certain  in- 
sects are  the  carriers  of  the  infective  organisms  of 
Texas  cattle  fever.  Manson  and  Ross  have  demonstrated 
that  a  certain  kind  of  fly  is  the  carrier  of  infection  for 
birds,  and  that  certain  species  of  mosquitoes  are  the  car- 
riers of  the  malarial  infection  for  human  beings.  They 
found  the  evolution  cycles  of  the  resistant  form  of  the, 
malaria  parasites  in  the  bodies  of  Anopheles,  while  in 
man  the  parasites  assume  the  asporulation  phase,  so  that 
man  is  merely  the  temporary  host  of  the  parasites.  Ac- 
cording to  Mattel,^  the  evolution  cycle  of  the  malaria 
parasites  consists,  therefore,  of  a  chain  of  two  rings — 
man  and  the  mosquito — man  infected  with  malaria  infects 
healthy  mosquitoes,  and  the  infected  mosquitoes  infect 
healthy  persons,  thus  completing  the  cycle. 

The  species  of  mosquito  which  appears  to  be  princi- 
pally, if  not  entirely,  concerned  in  carrying  malarial  in- 
fection to  man  is  the  Anopheles.  Mattel  found  that 
protection  against  mosquitoes  by  means  of  wire  screens 
at  windows  and  doors,  and  mosquito-netting,  served  to 

'^  Arch,  de  Vlnst.  Pasteur  de  Tunis,  1912. 

^  Zeitschr.  f.  Hyg.,  vol.  Ixxvi.,  p.  313. 

^  Centralbl.  f.  Baderiologie,  Bd.  xxviii.,  S.  189. 


PRE  VENTION  OF  MALARIA. 


393 


protect  against  malaria  while  sojourning  in  malarious 
localities.  Sambon  and  Low,  of  the  London  School 
of  Tropical  ^Medicine,  demonstrated  the  same  thing 
while  living  in  notoriously  malarious  localities  in  Italy. 
Dr.  Elliott,  a  member  of  the  Liverpool  Expedition  to 
West  Africa,  and  Prof.  Grassi,^  the  leader  of  an  Italian 
expedition  to  the  plains  of  Capaccio,  Italy,  report  similar 
results.  Wire  screens  and  mosquito-netting  were  found 
to  exclude  the  Anopheles  from  habitations,  but  failed  to 
exclude  the  non-infecting  culex. 

A.  Celli"  succeeded  in  limiting  the  incidence  of  malaria 


Fig.  59. — Mosquitoes  instrumental  in  the  dissemination  of  malarial  and  yellow 
fevers  :   I,  Anoplieles ;   2,  Stegomyia. 


in  the  railroad  employees  of  the  malarious  districts  of 
Italy  by  protecting  the  windows  with  wire  screening  of 
I  to  1.5  square  millimeters  mesh,  attaching  automatic 
locks  to  the  doors,  covering  the  chimneys  with  wire 
screening,  and  whitewashing  the  walls.  In  front  of  the 
doors  was  placed  an  antechamber  constructed  of  wire 
screening.  Those  who  were  obliged  to  work  out-of-doors 
at  night  had  all  exposed  portions  of  the  body  protected  : 
the  head  and  face  by  means  of  a  wire  mask,  and  the  hands 
by  means  of  gloves.     Of  the  207  officials  protected  in  this 

1  Centralbl.  f.  Bacteriologie,  Bd.  xxviii.,  S.  535. 

2  Ibid.,  Bd.  xxviii.,  S.  696. 


394  VITAL  CAUSES  OF  DISEASE. 

manner,  only  lo  contracted  malaria,  while  all  unprotected 
persons  in  the  same  locality  suffered  from  the  disease. 

Mansou^  reports  a  most  interesting  experiment  demon- 
strating the  direct  relation  of  mosquitoe^  to  malarial  in- 
fection. He  reports  the  successful  inoculation  in  London 
with  malaria  of  an  uninfected  individual  by  means  of 
mosquitoes  brought  from  Italy.  The  subject.  Dr.  Hanson's 
son,  submitted  on  three  occasions  to  the  bites  of  the 
imported  and  infected  mosquitoes,  with  the  result  that 
within  a  few  days  after  the  third  inoculation  symptoms 
of  tertian  malarial  fever  appeared,  together  with  the 
presence  of  the  corresponding  parasites  in  the  blood. 
Relief  was  promptly  afforded  by  the  administration  of 
quinin.  Similar  observations  are  said  to  have  been  made 
in  New  York  City  on  a  patient  in  Bellevue  Hospital,  who 
volunteered  for  the  purpose  of  the  experiment. 

The  Koch  method  of  preventing  malaria  consists  in 
the  removal  of  the  parasites  from  the  blood  of  those  suf- 
fering from  the  infection  ;  in  the  prevention  of  infection 
of  mosquitoes  by  making  it  impossible  for  them  to  bite 
those  carrying  the  parasites  in  their  blood.  Adults  that 
are  found  to  be  infected  with  malarial  parasites  are  each 
given  I  gram  of  quinin  in  lo  per  cent,  watery  solution 
for  four  to  six  days  ;  children  smaller  quantities.  Subse- 
quently they  are  given  each  week  2  grams  in  solution  on 
two  successive  days,  and  this  treatment  is  continued  for 
two  to  three  months. 

In  a  notoriously  malarious  region  it  is  impossible  to 
examine  the  blood  of  the  entire  population,  and  hence  it 
is  not  possible  to  prevent  the  infection  of  mosquitoes  and 
the  dissemination  of  the  disease  to  healthy  persons.  For 
this  reason  it  is  always  advisable  to  resort  also  to  the  plan 
advocated  by  Ross,  that  of  the  destruction  of  mosquitoes 
and  the  elimination  of  their  breeding-places.  The  com- 
bination of  the  Ross  and  Koch  methods  in  Cuba  and  the 
Canal  Zone  has  been  found  more  efficacious  than  is  either 
method  when  used  separately. 

^  British  Medical  Journal,  September  29,  1900,  p.  949. 


PRE  VENTION  OF  YELLO  W  FE  VER.  395 

Immunity  against  Malaria — Koch  believed  that  long- 
continued  residence  in  a  malarious  district  led  to  immu- 
nity as  indicated  by  the  absence  of  parasites  in  the  blood 
of  adults.  This  position  is  disputed  by  Glogner/  who 
does  not  regard  the  absence  of  parasites  in  the  blood  as 
proof  positive  of  freedom  from  malaria.  He  contends 
that  the  continued  infection  of  these  persons  is  shown  in 
the  marked  anemia  and  enlarged  spleens  which  they  pre- 
sent. Glogner  does  not  believe  that  there  is  any  immu- 
nity conferred  by  an  attack  of  malaria. 

Prevention  of  Yellow  Fever. — The  theor}-  of  the 
propagation  of  yellow  fever  by  mosquitoes  was  advanced 
by  Dr.  Carlos  J.  Finlay,  of  Havana,  as  early  as  1881.  In 
a  preliminary  report  of  the  investigations  of  a  commis- 
sion sent  to  Cuba  by  the  Surgeon-General  of  the  U.  S. 
Army,  to  study  yellow  fever,  which  Dr.  Walter  Reed  pre- 
sented before  the  American  Public  Health  Association  at 
Indianapolis,  Ind.,  October  24,  1900,  are  brought  forward 
most  interesting  and  important  facts  with  regard  to  this 
mode  of  dissemination  of  the  disease.  These  investiga- 
tions by  the  commission  confirm  the  observations  of  Dr. 
Henry  R.  Carter,  Surgeon  of  the  Marine-Hospital  Ser- 
vice at  Orwood  and  Taylor,  Miss.,  that  "  the  period  from 
the  first  (infecting)  case  to  the  first  group  of  cases  in- 
fected at  these  houses  (isolated  farm-houses)  is  generally 
from  two  to  three  weeks."  After  the  houses  had  become 
infected  susceptible  individuals  thereafter  visiting  the 
houses  for  a  few  hours  fall  sick  with  the  disease  in  the 
usual  period  of  incubation, — one  to  seven  days,^ 

Other  observations,  made  by  Reed  and  his  assistants  in 
Cuba,  confirmed  Dr.  Carter's  conclusions,  "  thus  pointing, 
as  it  seemed  to  us,  to  the  presence  of  an  intermediate 
host,  such  as  the  mosquito,  which,  having  taken  the 
parasite  into  its  stomach,  soon  after  the  entrance  of  the 
patient  into  the  non-infected  house,  was  able  after  a  cer- 
tain interval  to  convey  the  infecting  agent  to  other  indi- 

^  Vir chow's  Archiv,  vol.  clxii.,  p.  222. 

^  Philadelphia  Medical  Journal,  October  27,  1900. 


396  VITAL  CAUSES  OF  DISEASE. 

viduals,  thereby  converting  the  non-infected  house  into 
an  '  infected '  house.  This  interval  would  appear  to  be 
from  nine  to  sixteen  days  (allowing  for  the  period  of  in- 
cubation), which  agrees  fairly  closely  with  the  time  re- 
quired for  the  passage  of  the  parasite  from  the  stomach 
of  the  mosquito  to  its  salivary  glands." 

The  members  of  the  Yellow  Fever  Commission  of  the 
Liverpool  School  of  Tropical  Medicine,  Drs.  Durham 
and  Meyers,  were  impressed,  also,  with  the  importance 
of  Dr.  Carter's  observations.^ 

The  species  of  mosquito  which  serves  as  the  inter- 
mediate host  in  yellow  fever  has  been  identified  by  ly.  O. 
Howard,  Ph.D.,  Entomologist,  Department  of  Agricul- 
ture, Washington,   D.   C,   as  Stegomyia  fasciata,   Fabr, 

The  present  views  of  Dr.  Finlay  on  this  subject  are  as 
follows:  "First,  reproduction  of  the  disease,  in  a  mild 
form,  within  from  five  to  twenty-five  days  after  having 
applied  contaminated  mosquitoes  to  susceptible  subjects. 
Second,  partial  or  complete  immunity  against  yellow 
fever  obtained  even  when  no  pathogenous  manifestations 
had  followed  these  inoculations."^ 

Reed  and  his  assistants  failed  to  find  any  specific  micro- 
organisms in  the  blood  of  yellow-fever  patients,  nor  in 
the  cadavers  of  yellow-fever  subjects.  They  were  able, 
however,  to  inoculate  the  disease  successfully  by  means 
of  infected  mosquitoes  in  non-immune  subjects  after  ten 
to  twelve  days  had  elapsed  from  the  time  of  sucking  the 
blood  of  yellow-fever  patients  ;  the  period  of  incubation 
was  the  usual  one,  and  the  symptoms  developed  were 
typical. 

These  facts  tend  to  explain  many  of  the  points  that 
were  obscure  heretofore ;  notably,  the  fact  that  frost 
arrests  the  spread  of  yellow  fever.  This  fact  is,  no 
doubt,  due  to  the  destruction  of  infected  mosquitoes  by 
the  frost.  The  immunity  of  the  pine  belt  of  the  South- 
ern  States  may  also  be  explained  by  the  fact  that  in 

1  British  Medical  Journal,  pp.  656-7,  September  8,  1900. 
"^Medical  Record,  vol.  Iv.,  No.  21,  May  27,  1899. 


PRE  VENT/ON  OF  YELL  OW  FE  VER.  397 

these  regions  the  conditions  of  life  and   multiplicatioa 
are  unfavorable  to  mosquitoes. 

Extermination  of  the  mosquito  in  Havana  resulted  in 
the  virtual  eradication  of  yellow  fever.  In  an  official 
report  Major  W.  C.  Gorgas,  of  the  Army  Medical  Depart- 
ment, who  was  chief  sanitary  officer  of  General  Wood's 
staff,  says : 

"We  commence  June  with  the  city  free  from  yellow 
fever,  no  cases  being  on  hand.  This  is  probably  the  first 
time  Havana  has  ever  entered  June  free  from  yellow 
fever.     April  and  May  also  commenced  in  the  same  way. 

"Formerly  we  paid  no  particular  attention  to  the 
mosquito,  merely  disinfecting  for  yellow  fever,  as  we  do 
for  other  infectious  diseases.  The  amount  of  sanitary 
work  done  formerly  continues,  but  most  of  our  attention 
is  now  being  paid  to  the  destruction  of  mosquitoes. 

"The  suburbs  and  the  small  streams  in  the  suburbs 
have  been  thoroughly  cleaned  out,  and  pools  have  been 
oiled  and  drained.  The  Mayor  has  issued  an  order  pro- 
hibiting the  keeping  of  standing  water  within  the  city 
limits  unless  made  mosquito-proof.  This  is  being 
enforced,  and  all  standing  water  found  not  protected  is 
emptied  and  the  owner  fined." 

The  results  of  regulations  instituted  in  Cuba  by  the 
military  authorities  of  the  United  States  for  the  control 
of  yellow  fever  have  been  most  gratifying.  Aside  from 
a  diminution  of  the  incidence  of  malaria,  there  was  a 
rapid  diminution  of  the  death-rate  from  yellow  fever. 
While  the  average  death-rate  from  yellow  fever  had  been 
467  annually,  the  number  fell,  soon  after  the  introduc- 
tion of  the  preventive  regulations,  to  5  in  1901,  and  since 
September  28,  1901,  there  has  been  no  case  of  yellow 
fever  in  Havana. 

The  Killing  of  Flies. — It  has  been  well  established 
that  flies  serve  as  disseminators  of  a  number  of 
diseases  by  conveying  the  bacteria  on  the  surface  of 
their   bodies   to   food   materials.      Campaigns    against 


398  VITAL  CAUSES  OF  DISEASE. 

flies  have  been  organized  in  many  localities.  These 
efforts  are  directed  against  the  breeding  of  flies  and  the 
killing  of  adult  flies. 

Flies  breed  in  horse  manure  and  other  refuse  materials, 
as  garbage,  waste  paper,  and  decomposing  vegetable 
matter.  All  manure  and  sweepings  from  stables  should 
be  removed  at  frequent  intervals  so  as  to  prevent  flies 
from  breeding  in  the  materials.  Cleanliness  about 
stables,  backyards,  outhouses,  and  alleys  will  aid  greatly 
in  reducing  the  fly  nuisance. 

When  flies  congregate  on  the  exterior  of  buildings  or 
have  gained  access  to  the  buildings  an  effort  should  be 
made  to  kill  them.  Applying  a  torch  to  the  outside  of 
screened  windows  and  doors  on  which  flies  have  settled 
will  serve  to  scorch  their  wings  and  they  may  then  be 
swept  up  and  burned.  The  same  method  may  be  prac- 
tised indoors  when  large  numbers  of  flies  have  settled 
on  ceilings.  Spraying  insect  powder  into  a  room,  such 
as  pyrethrum  powder,  will  stupefy  the  flies  and  they  may 
then  be  swept  up  from  the  floor  and  burned. 

The  common  stable  fly,  Stomoxys  calcitrans,  has 
been  regarded  as  a  probable  disseminator  of  poliomye- 
litis. In  the  absence  of  complete  knowledge  it  will  be 
best  to  make  every  effort  to  control  the  breeding  of 
these  flies  in  horse  manure  and  to  prevent  the  entrance 
of  these  flies  into  houses. 

The  safest  and  most  efficient  fly  poisons  for  house- 
hold use  are  a  i  per  cent,  solution  of  formaldehyd  or  a 
I  per  cent,  solution  of  sodium  salicylate.  Neither  of 
these  solutions  is  highly  poisonous  to  children  and  can 
cause  no  fatal  poisoning  to  anyone  drinking  a  small 
quantity  of  either  solution. 

The  Killing  of  Mosquitoes  in  the  City. — C.  Fermi  and 
S.  lyumbao^  give  brief  biologic  notes  on  the  mosqui- 
toes which  most  commonly  infest  cities.     As  insecti- 

^Centralbl.f.  Bad.,  i  abst.,  pp.  179-185,  1900. 


PREVENTION  OF  YELLOW  FEVER.  399 

cides  against  mosquito  larvae,  the  authors  used  petroleum 
and  chrysanthemum  powder  with  good  success.  Several 
substances  were  experimented  with  for  the  purpose  of 
discovering  means  for  the  prevention  of  the  too  rapid 
evaporation  of  petroleum  from  the  surface  of  infested 
water.  The  substances  which  were  spread  upon  the 
surface  of  the  petroleum  for  this  purpose  were  lanolin, 
vaselin,  tar,  naphtalin,  olive  oil,  flaxseed  oil,  castor  oil, 
and  lard.  Vaselin  and  tar  spread  rapidly  over  the  sur- 
face of  the  oil  without  coagulating.  A  large  number  of 
plant  substances  were  tried  in  combination  with  chrys- 
anthemum powder  in  the  destruction  of  mosquito  larvae. 
For  the  destruction  of  adult  mosquitoes  the  authors  tried 
fumigation  with  a  number  of  substances,  among  which 
the  following  gave  the  best  results  :  chloroform,  turpen- 
tine and  vinegar,  sulphuric  ether,  tobacco  fumes,  and 
eucalyptus  fumes. 

The  relation  of  marshy  ground  to  yellow  fever  is  prob- 
ably less  direct  than  that  of  its  relation  to  malaria,  since 
the  Stegomyia  appears  to  breed  in  water-tanks  and  places 
of  that  character  rather  than  in  marshes,  as  is  the  case 
with  the  Anopheles.  The  experience  of  the  military 
authorities  of  the  United  States  during  the  occupation 
of  Cuba  demonstrated  that  general  hygienic  measures 
along  with  the  drainage  of  the  marshes  had  onlv  a  mod- 
erate  influence  in  reducing  the  incidence  of  yellow  fever 
during  the  first  year  of  the  occupation.  During  the  sec- 
ond year,  when,  in  addition  to  this,  energetic  measures 
were  employed  to  eradicate  the  mosquitoes,  the  influence 
upon  the  incidence  of  yellow  fever  was  most  striking, 
and  with  the  continuation  of  the  measures  it  has  con- 
tinued so  up  to  the  present  time. 

During  the  experiments  with  petroleum  it  was  found 
that  5  c. c.  per  square  meter  of  water  surface  killed  all 
mosquito  larvae.  It  was  not  found  necessary  to  renew 
the  kerosene  upon  the  surface  oftener  than  once  in  four- 
teen davs. 


400  VITAL   CAUSES  OF  DISEASE. 

Dr.  M.  J.  Rosenau^  studied  the  relative  efficiency  of 
formaldehyd  and  sulphur  dioxid  as  disinfectants  against 
mosquitoes.  Young  healthy  mosquitoes  were  exposed 
to  the  disinfectants  in  pill-boxes  and  at  the  same  time 
test-objects  containing  bacteria  were  also  exposed  to  the 
gas  for  purposes  of  comparison. 

Rosenau  reached  the  conclusion  that  formaldehyd  is 
a  feeble  insecticide.  "To  succeed  in  killing  all  the 
mosquitoes  in  a  closed  space  with  formaldehyd  gas,  the 
following  requirements  are  essential  :  A  very  large  vol- 
ume of  gas  must  be  liberated  quickly,  so  that  it  may 
diffuse  to  all  portions  of  the  space  in  sufficient  concen- 
tration. The  room  must  have  all  the  cracks  and  chinks 
where  the  insects  may  breathe  the  fresh  air  carefully 
sealed  by  pasting  strips  of  paper  over  them.  The  room 
must  not  contain  heavy  folds  of  drapery,  clothing,  bed- 
ding, or  fabrics  in  heaps,  or  so  dispersed  that  the  insects 
may  hide  away  from  the  full  effects  of  the  gas." 

With  regard  to  sulphur  dioxid,  the  results  were  far 
more  satisfactory.  Rosenau  states  that  "sulphur  dioxid 
is  unexcelled  as  an  insecticide.  Very  diluted  atmos- 
pheres of  the  gas  will  quickly  kill  mosquitoes.  It  is  as 
efficacious  for  this  purpose  when  dry  as  when  moist, 
whereas  the  dry  gas  has  practically  no  power  against  bac- 
teria. Contrary  to  formaldehyd  it  has  surprising  powers 
of  penetrating  through  clothing  and  fabrics,  killing  the 
mosquitoes,  even  when  hidden  under  four  layers  of  towel- 
ing, in  one  hour's  time — and  in  very  diluted  proportions. 
This  substance,  which  has  so  long  been  disparaged  as  a 
disinfectant  because  it  fails  to  kill  spores,  must  now  be  con- 
sidered as  holding  first  rank  in  disinfection  against  yellow 
fever,  malaria,  filariasis,  and  other  insect-borne  diseases. " 

Destruction  of  Vermin. — Vermin  of  other  sorts  than 
mosquitoes  transmit  disease.  Rats  have  been  known  to 
carry  the  plague  from  ships  ;  flies  have  carried  tubercu- 
losis and  typhoid  ;  bedbugs  and  fleas  are  considered 
dangerous. 

'^Bulletin  No.  6  of  the  Hygienic  Laboratory,  1901. 


DESTRUCTION  OF  VERMIN.  401 

Experiments  in  disinfection  for  getting  rid  of  vermin 
have  shown  that  the  work  is  one  of  some  difficulty.  In 
the  Antiales  de  PJiarmacie  a  report  is  given  of  the  inves- 
tigations of  Mr.  V.  Haazen. 

According  to  Mr.  Haazen' s  results,  bedbugs  resist  ex- 
posure for  twenty-four  hours  to  an  atmosphere  contain- 
ing 6  grams  of  foruialdehyd  gas  per  cubic  meter  (or  2.6 
grains  per  cubic  foot). 

Bedbugs  were  partly,  but  not  entirely,  killed  by  a 
concentration  of  8  grams  per  cubic  meter  (3.5  grains 
per  cubic  foot).  All  perished  when  the  concentration 
was  made  9  grams  per  cubic  meter  (3. 9  grains  per  cubic 
foot). 

The  complete  destruction  of  bedbugs  is  accomplished 
also  by  burning  25  grams  of  sulphur  for  each  cubic 
meter  of  space  (or  10.7  grains  per  cubic  foot). 

Flies  and  mosquitoes  are  killed  by  burning  2  grams 
of  solidified  formaldehyd  for  each  cubic  meter  of  air 
(0.88  grains  per  cubic  foot). 

Fleas  require  for  destruction  7  grams  of  the  formal- 
dehyd per  cubic  meter  (3.08  grains  per  cubic  foot). 

For  rats  and  mice  an  exposure  of  thirty-six  hours  to 
an  atmosphere  containing  15  grams  of  formaldehyd  per 
cubic  meter  (6.6  grains  per  cubic  foot)  was  found  neces- 
sary. 

The  extermination  of  rats,  because  they  are  the 
carriers  of  plague-infection,  has  become  the  duty  of  all 
civilized  governments.  The  Ivocal  Government  Board  of 
England  recognizes  this  fact  in  a  circular  to  the  sanitary 
authorities  on  the  risk  of  importing  the  disease  in  ships 
infested  with  plague-infected  rats  and  the  precautions 
necessary  to  prevent  such  introduction.  On  other  grounds 
it  would  be  well  if  these  justly  detested  animals  could  all 
be  killed.  These  pests  have  been  supposed  to  be  scaven- 
gers, but  the  answer  to  the  plea  is  that  the  filth  upon 
which  they  live  is  unnecessary,  and  even  a  danger. 

Simon  believed  that  plague  was  carried  by  the  fleas  with 
which  rats  are  commonly  infested  ;  but  Dr.  Nuttall,  who 

26 


402  VITAL   CAUSES  OF  DISEASE. 

made  an  extensive  study  of  the  subject,  claimed  that  his 
researches  did  not  bear  out  Simon's  theory.  Prof.  Ash- 
burton  Thompson,  in  an  account,  of  the  plague  in  New 
South  Wales,  was  convinced  the  disease  reached  Sidney 
through  the  rats  on  vessels  from  Noumea,  at  which  place 
the  plague  existed.  The  medical  commission  of  the 
Japanese  Government  found  that  to  avoid  the  spread  of 
bubonic  plague  rats  must  be  exterminated.  An  effective 
method  of  doing  this  has  been  suggested — namely,  with 
sulphurous  acid  forced  into  all  parts  of  the  vessel  and  re- 
tained there  for  twenty-four  hours. 

Extermination  of  rats,  by  the  generation  of  sulphurous 
acid  gas  of  a  high  strength,  has  been  successfully  tried 
on  the  "Jelunga,"  a  steamer  of  the  British  India  line. 
The  apparatus  used  was  a  small  cylinder  in  which  rolled 
sulphur  was  burned  until  it  vaporized,  and  air  being  ad- 
mitted into  the  chamber  where  this  vaporizing  took  place 
the  combination  of  oxygen  and  sulphur  vapors  furnished 
the  sulphur  dioxid  gas.  The  hatches  of  the  "Jelunga" 
were  closed  and  the  gas  admitted.  The  space  to  be  oper- 
ated on  held  2100  cubic  meters.  The  next  day  when  the 
vessel  was  opened  dead  rats  were  lying  about  and  all 
other  forms  of  vermin  were  also  killed. 

It  is  the  rat  flea,  Pulex  cheops,  which  carries  the 
plague  bacillus  from  infected  rats  to  healthy  rats  and  to 
human  beings.  The  rat  flea  does  not  ordinarily  feed  on 
human  beings.  When,  however,  its  natural  host  is  not 
available  it  attacks  human  beings.  This  explains  the 
fact  that  epidemics  of  plague  in  human  beings  are  fre- 
quently preceded  by  fatal  disease  among  rats. 

Relation  of  Insects  to  the  Spread  of  Disease. — 
Within  recent  years  we  have  come  to  regard  many  of 
the  common  insect  pests  with  suspicion.  This  is  espe- 
cially true  since  the  discovery  by  Ross  that  the  mosquito 
plays  the  part  of  definitive  host  for  the  parasite  of  mala- 
ria. The  earliest  positive  demonstration  of  the  instru- 
mentality of  insects  in  the  dissemination  of  disease  was 
made  by  Smith  and  Kilbourne.     They  demonstrated  that 


INSECTS  AND    THE  SPREAD   OF  DISEASE.    403 

the  tick — Boophilus  bovis — infesting  the  cattle  of  the 
Southern  States  is  instrumental  in  disseminating  the 
disease  Texas  fever  from  sick  cattle  to  the  well.  Within 
the  last  few  years  a  number  of  other  diseases  have  been 
found  to  be  disseminated,  wholly  or  in  part,  through  the 
agency  of  insects.  The  relation  of  insects  to  the  spread 
of  disease  may  be  divided  into  several  classes  according 
to  the  nature  of  the  organisms  and  the  mode  of  trans- 
mission. 

I.  Insects  may  convey  pathogenic  bacteria  on  their 
bodies  by  coming  in  contact  with  infective  materials,  as 
tubercular  sputum,  typhoid,  dysentery,  or  cholera  stools. 
Bacteria  may  be  conveyed  considerable  distances  and 
then  deposited  on  food-materials,  and  thus  form  a  new 
focus  of  infection.  The  insect  which  is  probably  most 
frequently  the  disseminating  agent  of  such  diseases  is 
the  common  house-fly — Musca  domestica. 

An  epidemic  of  typhoid  fever  in  Chicago  during  the 
summer  of  1902  was  most  severe  in  one  of  the  wards  of 
that  city.  In  this  ward,  containing  one-thirty-sixth  of 
the  population  of  the  city,  there  occurred  over  one- 
seventh  of  the  deaths  from  this  disease.  The  epidemic 
could  not  be  attributed  to  the  character  of  the  food  or  to 
the  water-supply,  as  these  did  not  differ  in  any  respect 
from  the  supplies  of  neighboring  wards.  An  examination 
of  the  sewerage  of  the  ward  revealed  the  fact  that  many 
of  the  sewers  were  too  small  to  carr}-  the  sewage.  Only 
48  per  cent,  of  the  houses  had  sanitary  plumbing,  while 
7  per  cent,  had  defective  plumbing,  22  per  cent,  had 
water-closets  with  intermittent  water-supply,  and  11  per 
cent,  had  privies  with  no  sewer  connections.  Flies  caught 
in  two  undrained  privies,  on  the  fences  of  two  yards,  on 
the  walls  of  two  houses,  and  in  the  room  of  a  typhoid 
patient  were  inoculated  into  eighteen  tubes,  and  from 
five  of  these  tubes  the  typhoid  bacillus  was  isolated.  It 
is  evident  that  this  epidemic  was  brought  about  by  the 
dissemination  of  the  infectious  material  by  flies. 

Roaches    may   also   become    agents   in    disseminating 


404  VITAL   CAUSES  OF  DISEASE. 

typhoid,  dysentery,  and  cholera  by  coming  into  contact 
with  infective  material  in  drains  and  sewers  and  subse- 
quently carrying  the  infectious  materials  on  their  bodies 
to  food-materials. 

2.  Flies  may  carry  tubercle  bacilli  within  their  bodies 
when  they  are  permitted  to  feed  on  tubercular  sputum. 
Live  tubercle  bacilli  have  been  obtained  from  the  feces 
of  flies  fed  on  tubercular  sputum.  Consequently  the 
feces  of  flies  may  be  a  source  of  danger.  Flies  may  also 
serve  to  carry,  in  a  similar  manner,  the  micro-organisms 
of  a  number  of  other  infectious  diseases,  as  diphtheria, 
pneumonia,  erysipelas,  suppuration,  and  possibly  of  small- 
pox, though  we  have  as  yet  no  positive  proof  of  the  con- 
veyance of  small-pox  in  this  manner.  Dr.  Ficker  ^  has 
found  that  flies  fed  on  typhoid  cultures  give  off  the  bacilli 
twenty-three  days  after  infection.  Typhoid  bacilli  were 
found  in  the  intestine  nine  days  after  feeding  on  typhoid 
materials. 

3.  Suctorial  insects,  by  sucking  the  blood  of  persons 
or  animals  containing  certain  bacteria  or  animal  parasites, 
may  transmit  these  organisms  by  means  of  the  proboscis 
to  healthy  persons  or  animals.  Gad-flies  or  horse-flies 
may  carry  anthrax  bacilli  in  this  manner  and  infect 
healthy  persons  or  animals.  The  common  bedbug  is 
believed  to  be  instrumental  in  disseminating  the  parasite 
of  relapsing  fever  in  a  similar  manner.  Dr.  Karlinski  - 
believes  that  bedbugs  are  the  direct  transmitting  agents 
of  relapsing  fever.  The  spirilla  were  found  in  the  intes- 
tinal contents  after  twenty  days,  while  they  disappeared 
rapidly  in  lice  and  fleas.  The  recent  studies  by  Toyoda^ 
bring  strong  evidence  that  the  clothes  louse,  Pediculus 
vestimenti,  is  the  carrier  of  the  spirochaete  of  relapsing 
fever,  but  he  could  find  no  evidence  that  the  bedding 
could  carry  the  organism.  The  spirochsetes  undergo 
multiplication  in  the  body  of  the  louse,  and  are  later 

1  Arch.  f.  Hygiene,  Bd.  xlvi.,  S.  274. 

*  Centralbl.  f.  Baderiologie,  Bd.  xxxi.,  S.  566. 

3  Zeitschr.  fur  Hygiene,  Bd.  Ixvii.,  1913,  p.  313. 


INSECTS  AND    THE  SPREAD   OF  DISEASE.     405 

found  in  the  head  in  the  vicinity  of  the  glandular  organs. 
Toyoda  believes  the  louse  to  be  infectious  seven  days 
after  taking  the  blood  of  an  infected  person.  Typhus 
fever  is  also  disseminated  by  biting  insects,  and  the 
clothes  louse  is  probably  most  commonly  the  carrier, 
thoueh  the  bedbug-  has  also  been  claimed  to  be  the 
carrier  of  this  disease.  The  agency  of  fleas  in  the  dis- 
semination of  bubonic  plague  has  been  demonstrated. 
Gauthieri  shows  that  fleas  transmit  plague  from  rat  to 
rat.  Fleas  taken  from  a  living  infected  rat  caused  plague 
in  nine  of  ten  rats.  The  fleas  of  these  animals  were  also 
found  to  bite  human  beings,  and  Gauthier  therefore  con- 
cludes that  the  connection  between  the  presence  of  in- 
fected rats  in  a  district  and  the  sufferers  from  plague  is 
represented  by  these  insects.  Dr.  Zirolia-  found  Bacillus 
pestis  in  fleas  fed  on  infected  mice.  These  bacilli  were 
found  to  be  virulent  seven  to  eight  days  after  infection. 
The  bacilli  were  also  demonstrated  in  the  feces.  The 
work  of  the  English  Plague  Commission^  leaves  no 
doubt  that  this  is  the  mode  of  dissemination  of  the  dis- 
ease from  infected  to  healthy  rats,  and  the  dissemina- 
tion of  the  disease  to  human  beings  occurs  through  the 
bite  of  infected  rat  fleas.  The  flea  which  is  found  most 
commonly  on  rats  in  warm  countries  is  Pulex  cheops. 
This  flea  occurs  on  both  Mus  rattus  and  Mus  decumanus. 
The  rat  flea  in  northern  countries,  where  observations 
have  been  made,  is  Ceratophyllus  fasciatus.  This  flea  is 
also  found  on  the  common  house  mouse,  Mus  musculus, 
but  less  commonly  than  Ctenopsylla  musculi.  The  flea 
which  is  most  likely  to  harbor  on  human  beings  is 
Pulex  irritans,  though  Pulex  cheops,  the  common  rat 
flea,  will  also  bite  human  beings  when  its  natural  host  is 
absent. 

Fleas  are  instrumental  in  carrjang  trypanosomes  to  rats. 
Trypanosomes  have  also  been  found  in  the  stomachs  of 

1  Bull,  de  VAcad.  de  Med.,  December  16,  1902. 

2  Centralbl.  f.  Baderiologie,  Bd.  xxxi.,  S.  87. 
^  Jour,  of  Hygiene,  March,  1908. 


4o6  VITAL    CAUSES  OF  DISEASE. 

lice  feeding  on  the  blood  of  infected  animals.  In  Africa 
trypanosomes  are  transmitted  to  horses,  cows,  sheep,  and 
dogs  through  the  bite  of  the  tsetse  fly,  Glossina  morsitans. 
Sleeping  sickness,  a  trypanosomiasis  in  human  beings 
prevalent  in  Africa,  is  transmitted  by  another  species  of 
tsetse  fly — Glossina  palpalis. 

4.  The  transmission  of  the  malarial  and  yellow-fever 
parasites  to  man,  as  well  as  the  transmission  of  similar 
parasites  to  birds,  through  the  agency  of  certain  species 
of  mosquitoes,  is  now  well  established.  In  the  transmis- 
sion of  these  diseases  the  insects  are  not  merely  the  car- 
riers of  the  parasites,  but  also  serve  the  important  innt- 
tion  of  hosts  for  the  parasites  in  that  a  certain  phase  of 
the  life-cycle  of  the  parasite  is  passed  in  the  bodies  of 
these  insects.  Without  either  man  or  the  specific  mos- 
quito the  malarial  and  yellow-fever  parasites  would 
perish,  as  it  is  believed  that  both  are  necessary  for  the 
completion  of  the  life-cycles  of  the  parasites.  The  Anoph- 
eles is  the  species  of  mosquito  instrumental  in  the  trans- 
mission of  malaria,  while  the  Stegomyia  is  the  species 
instrumental  in  the  transmission  of  yellow  fever.  These 
insects  suck  the  blood  of  patients  suffering  from  these 
diseases,  and  then  the  fecundated  female  elements  pene- 
trate the  wall  of  the  stomach  of  the  mosquito  and  become 
encysted.  After  maturation  of  the  sporocysts  they  rup- 
ture into  the  body  cavity,  whence  the  young  parasites 
find  their  way  into  the  salivary  glands  of  the  mosquito 
and  are  then  projected  through  the  proboscis  into  the 
tissues  of  healthy  persons  during  the  act  of  sucking 
blood.  In  the  transmission  of  parasites  similar  in  nature 
to  the  malarial  organism  from  diseased  to  healthy  birds — 
sparrows,  canaries,  crows,  buzzards,  etc. — it  is  believed 
that  the  common  Culex  variety  of  mosquito  is  the  dis- 
seminating agent.  In  the  diseases  of  birds  the  mosquito 
plays  the  same  part  as  in  the  transmission  of  malaria  and 
yellow  fever  in  that  the  parasites  undergo  one  phase  of 
their  life-cycle  in  the  bodies  of  the  mosquitoes.  The 
conditions   necessary  for   the   occurrence  of  malaria   or 


INSECTS  AND    THE  SPREAD   OF  DISEASE.    407 

yellow  fever  in  a  community  are  the  following:  {a)  The 
primar}^  existence  or  importation  of  a  case  of  the  particu- 
lar disease  ;  {b)  the  presence  of  the  particular  genus  of 
mosquitoes  ;  (r)  the  infection  of  the  mosquitoes  by  suck- 
ing the  blood  of  the  patient  ;  {d)  the  presence  of  non- 
immune persons  in  the  community  to  which  the  infected 
mosquitoes  may  transmit  the  disease  after  the  lapse  of 
time  necessary  for  the  maturity  of  the  young  parasites 
in  the  body  of  the  mosquito  ;  (<?)  the  continuance  of 
the  epidemic  subsequent  to  the  occurrence  of  secondar}' 
cases  requires  suitable  climatic  and  telluric  conditions  for 
the  breeding  of  the  mosquitoes  ;  and  {/)  suitable  tem- 
perature for  development  of  the  zygote  in  the  stomach 
of  the  mosquito. 

The  prevention  of  the  dissemination  of  either  malaria 
or  yellow  fever  requires  observation  of  the  following 
conditions  :  {a)  It  is  necessary  to  prevent  mosquitoes 
from  gaining  access  to  patients  suffering  from  the  disease 
by  suitable  screening,  because  non-infected  mosquitoes 
cannot  transmit  the  disease  ;  {b)  the  protection  of  healthy 
persons  from  mosquito-bites  ;  in  this  manner  they  can  be 
kept  free  from  the  disease  even  though  infected  mosquitoes 
exist  in  the  community  ;  {c)  the  adoption  of  measures  for 
the  destruction  of  mosquitoes  in  all  stages  of  their  devel- 
opment— i.  e.^  draining  all  marshy  places,  pouring  oil  on 
all  stagnant  waters  that  cannot  be  drained,  protecting 
water-tanks,  etc.,  so  as  to  prevent  mosquitoes  from  gain- 
ing access  thereto  ;  destruction  of  adult  mosquitoes  in 
houses  by  means  of  insecticides,  as  petroleum,  pyre- 
thrum  powder,  or  sulphur  dioxid  gas. 

The  transmission  of  filaria  by  means  of  mosquitoes 
presents  certain  phases  which  are  similar  to  those  apper- 
taining to  the  transmission  of  malaria  and  yellow  fever. 
The  parasite  is  taken  into  the  stomach  of  the  mosquito, 
and  transmission  to  other  individuals  takes  place  after  it 
has  undergone  a  certain  phase  of  its  development  in  the 
body  of  the  mosquito.  The  young  parasites  are  lodged 
in  the  sublingual  region   at  the  root  of  the  proboscis, 


408  VITAL  CAUSES  OF  DISEASE. 

whence  they  find  their  way  into  the  saliva  and  are  trans- 
mitted in  the  act  of  biting.  Both  Cnlex  and  Anopheles 
are  believed  to  be  instrumental  in  the  transmission  of 
filaria. 

Culex  fatigans  is  now  regarded  as  the  transmitting 
agent  of  the  virus  of  dengue,  though  no  organism  has 
been  demonstrated. 

5.  It  is  regarded  as  a  proved  fact  that  typhus  fever 
is  disseminated  by  the  clothes  louse,  Pediculus  vestimenti, 
and  in  efforts  to  eradicate  typhus  fever  our  chief  effort 
should  be  directed  toward  the  removal  of  lice  from  the 
entire  population  of  an  infected  district.  This  is  ac- 
complished by  sending  disinfecting  trains  of  cars  to 
the  infected  area  and  disinfecting  the  bodies  and  the 
clothing  of  all  the  inhabitants. 

6.  Still  another  manner  in  which  insects  transmit 
disease  is  that  of  the  transmission  of  Texas  cattle 
fever  by  the  cattle-tick — Boophilus  bovis.  This  mode 
of  transmission  differs  from  those  already  considered  in 
that  the  fecundated  female  tick  sucks  the  blood  of  in- 
fected cattle  and  transmits  the  parasite  to  her  eggs,  and 
the  young  ticks  in  turn  transmit  the  parasite  to  healthy 
cattle  while  sucking  their  blood.  Two  generations  of 
ticks  are  necessary  for  the  transmission  of  the  disease 
from  sick  to  healthy  cattle.  The  exact  manner  of  the 
transmission  of  the  parasite  from  the  infected  tick  to  the 
egg  and  offspring  has  not  been  demonstrated. 

A  tick — Dermacentor  occidentalis — is  instrumental  in 
the  transmission  of  the  "spotted  fever"  of  the  Rocky 
Mountain  regions.  Another  tick — Ornithodoris  moubata 
— is  instrumental  in  the  transmission  of  African  tick 
fever. 

Remedies  for  Fleas. — The  subject  of  domestic  pests 
has  been  fully  treated  in  publications  of  the  Division  of 
Entomology  of  the  Department  of  Agriculture,  and  the 
work  of  the  Division  has  been  supplemented  by  interest- 
ing experiments  along  the  same  line  by  several  of  the 
State  Experiment  Stations.      Especially  valuable  results 


REMEDIES  FOR  FLEAS.  4^9 

have  recently  been  obtained  in  experiments  with  remedies 
for  the  extermination  of  fleas. 

At  times  fleas,  especially  the  dog-  and  cat-flea,  become 
one  of  the  most  troublesome  of  household  pests.  Nu- 
merous remedies  have  been  recommended  for  ridding 
houses  and  animal  pets  of  these  pests,  but  these  reme- 
dies have  not  proved  effective  under  all  circumstances. 
The  Division  of  Entomology  recommends  thorough 
sweeping  and  cleaning  of  floors  and  walls,  the  disuse  of 
carpets  and  mattings  and  their  replacement  with  rugs, 
which  are  to  be  removed  and  beaten  at  frequent  inter- 
vals. It  is  also  recommended  that  infested  carpets  and 
other  such  objects  be  dusted  with  pyrethrum  powder  or 
sprinkled  with  benzine.  Failing  in  these  measures  the 
removal  of  carpets  and  thorough  scrubbing  with  hot 
soapsuds  are  recommended. 

In  some  experiments  made  in  Scotland  by  R.  S.  Mac- 
Dougall  it  was  found  desirable  to  cleanse  dog-kennels 
with  lime-wash,  to  wash  dogs  and  cats  with  soapsuds, 
and  then  sprinkle  them  thoroughly  with  pyrethrum 
powder.  The  use  of  creolinated  water  in  a  lo  per  cent, 
solution  was  also  found  effective  in  ridding  houses  of 
fleas  and  in  destroying  these  insects  upon  dogs.  In  some 
parts  of  JMexico,  according  to  IMacDougall,  brooms  are 
made  of  Asclepias  curassivica,  a  kind  of  milk-weed,  and 
walls  and  floors  of  infested  houses  are  swept  with  these 
brooms.  The  odor  of  this  plant  when  thus  utilized  has 
been  found  to  check  the  spread  of  the  flea  nuisance  in 
houses. 

At  the  Vermont  Experiment  Station  satisfactory  results 
were  obtained  by  sprinkling  infested  animals  and  kennels 
with  kerosene  emulsion,  but  this  remedy  is  not  appli- 
cable in  households  on  account  of  the  disagreeable  odor 
and  other  effects  of  kerosene.  At  the  Michigan  Experi- 
ment Station  pyrethrum  gave  excellent  results  in  rid- 
ding houses  of  fleas.  This  remedy,  however,  has  not 
always  proved  effective,  and  in  some  instances  was  appa- 
rentlv  without  effect. 


4IO  VITAL  CA  USES  OF  DISEASE. 

In  experiments  at  the  New  Hampshire  Experiment 

Station  it  was  found  that  creolin  was  the  most  satisfac- 
tory remedy.  This  may  be  used  in  a  diluted  form  as  a 
disinfectant,  deodorant,  insecticide,  and  repellant.  It 
was  found  that  a  3  per  cent,  solution  was  sufficiently 
strong  for  ordinary  purposes.  Infested  dogs  and  cats  may 
be  thoroughly  washed  with  this  mixture,  which  may  be 
made  slightly  weaker  for  cats  on  account  of  the  greater 
sensitiveness  of  the  fur  of  this  animal.  The  animals 
may  also  be  dipped  in  the  solution.  Commercial  creo- 
lin may  be  purchased  at  drug-stores  for  about  25  cents 
a  pint.  A  3  per  cent,  mixture  with  water  ma}"  be  made 
by  adding  4  teaspoonfuls  of  creolin  to  a  quart  of  water 
or  4  tablespoonfuls  to  a  gallon.  A  2  per  cent,  solution 
is  obtained  by  adding  2  teaspoonfuls  to  the  quart  or  2 
tablespoonfuls  to  the  gallon  of  water.  When  thoroughly 
shaken,  the  mixture  is  ready  for  use.  The  mixture  may 
be  applied  to  the  animal  with  the  hands  or  a  brush,  or, 
as  already  suggested,  the  animal  may  be  submerged  in 
the  solution  for  about  five  minutes.  The  animal  requires 
no  further  care  or  treatment  after  the  application.  This 
treatment  not  only  destroys  the  fleas,  but  also  serves  as  a 
deodorant. 

In  treating  floors  it  is  recommended  that  all  unneces- 
sary objects  be  removed,  and  that  cracks  and  crevices 
should  be  scrubbed  with  a  5  per  cent,  solution  of  creolin. 
The  bedding  of  animal  pets  infested  with  fleas  should  be 
thoroughly  saturated  from  time  to  time  with  a  5  per 
cent,  solution  of  creolin. 

Two  other  remedies  which  are  quite  eflfective  against 
fleas  have  been  recommended  with  some  reservation,  but 
these  remedies  are  perhaps  too  dangerous  for  general  use 
in  households.  Reference  is  had  to  fumigation  with 
carbon  disulphid  and  hydrocyanic  acid. 

The  above-mentioned  remedies  include  nearl}-  all  the 
substances  which  have  been  found  effective  in  destroying 
fleas.  In  combating  these  insects,  however,  it  should 
always  be  remembered,  as  the  Division  of  Entomology 


ANIMAL  PARASITES.  411 

of  the  Department  of  Agriculture  points  out,  that  the 
infestation  of  houses  is  due  to  the  presence  of  flea-in- 
fested dogs  or  cats,  which  are  allowed  to  occupy  some 
portion  of  the  house  during  a  part  or  all  the  time. 
Fleas  normally  live  as  parasites  upon  the  animals  which 
they  infest  or  upon  man,  but  eggs  which  are  laid  by  the 
parasitic  aduit  insects  may  fall  upon  the  floor  or  the  car- 
pets of  houses,  and  after  hatching,  may  live  for  an  indef- 
inite period  upon  the  dust  which  accumulates  under  car- 
pets and  in  the  cracks  of  floors.  In  ridding  a  house  of 
fleas  attention  should,  therefore,  be  directed  first  to  treat- 
ment of  the  dogs  or  cats  from  which  infestation  originates. 
This  treatment,  if  done  in  a  thorough  manner,  will  rid 
the  animal  pets  of  fleas  and  will  prevent  re-infestation  of 
the  house  after  a  thorough  application  of  the  insecticides. 

Animal  Parasites. — Animal  parasites  are  living  or- 
ganisms which  live  in  or  upon  other  living  organisms 
for  the  purpose  of  obtaining  nutrition,  and  live  there 
either  temporarily  or  permanently.  The  parasitism  is 
of  different  forms  and  various  grades  in  the  different 
parasites,  and  Leuckart  has  divided  them  into  two 
classes — temporary  and  permanent  parasites.  Among 
the  temporary  parasites  may  be  mentioned  the  flea 
(Pulex  irritans),  the  bed-bug  (Cimex  lectularia),  the 
leech  (Hirudo  medicinalis),  the  different  species  of  mos- 
quitoes, as  well  as  others  which  seek  the  host  merely 
for  the  purpose  of  sucking  blood,  and  depart  after  having 
satisfied  their  hunger.  Their  entire  existence  from  the 
^^%  to  the  adult  stage  is  passed  outside  the  body  of  the 
host.  These  parasites  attack  only  the  surface  of  the 
body  of  the  host,  and  hence  have  been  called  epizoa  or 
ectoparasites,  though  these  terms  do  not  apply  to  the 
temporary  parasites  alone. 

The  permanent  parasites  pass  a  portion  or  even  their 
entire  life  in  or  upon  the  body  of  the  host,  so  that  they 
obtain  lodging  as  well  as  nutrition  from  the  affected 
host.  These  parasites  usually  live  within  the  body  of  the 
host,  principally  in  those  organs  which  are  readily  acces- 


412  VITAL  CAUSES  OF  DISEASE. 

sible  from  the  outside,  as  the  intestines  and  their  ap- 
pendages, though  others  invade  the  muscles,  lymphatic 
system,  circulatory  system,  bone-marrow,  brain,  etc. 
In  many  instances  it  is  not  possible  to  demonstrate  a 

definite  influence  exerted  by  the  parasite  upon  the  host 
organism.  But  in  other  instances  the  presence  of  the 
parasite  is  manifested  by  its  particular  location,  the 
number  of  parasites,  the  movements  induced,  or  the 
nutrition  absorbed  from  the  host,  in  consequence  of 
which  they  induce  more  or  less  marked  disturbances  of 
the  health  of  the  host,  or  may  even  lead  to  its  destruc- 
tion. Certain  of  the  animal  parasites  evidently  produce 
poisonous  metabolic  or  excretory  products  which  give 
rise  to  definite  symptoms.  There  is  evidence  to  believe 
that  in  malaria,  yellow  fever,  trypanosomiasis,  and  other 
diseases  the  grave  symptoms  produced  by  the  infection 
are  due  to  poisons  generated  by  the  parasites  as  the 
result  of  their  development  and  metabolism. 

Protozoa. — The  protozoa  are  unicellular  animal  organ- 
isms which  multiply  in  two  ways  :  sexual  and  asexual 
development.  The  asexual  development  takes  place 
within  the  body  of  the  host  under  favorable  conditions, 
and  as  a  result  there  may  be  an  enormous  increase  in  the 
number  of  individuals.  The  sexual  mode  of  develop- 
ment serves  for  the  preservation  of  the  species  in  that 
it  supplies  a  phase  in  the  life  of  the  parasite  when  it 
may  be  transplanted  from  one  host  to  another.  Most 
of  the  protozoa  are  nourished  either  by  osmosis  or  by  the 
invagination  of  small  food-particles.  One  class  of  the 
protozoa,  the  suctoria,  possess  small  suctorial  tubes 
through  which  they  take  up  their  nutrition. 

Amoeba  coli  (Loesch). — This  parasite  was  found  by 
Koch  and  Gaffky  in  1883  in  Egypt  in  the  intestines  of 
five  cases  of  dysentery  that  came  to  autopsy.  Since  that 
time  the  parasite  has  been  found  in  all  parts  of  the  civi- 
lized world,  and  is  regarded  as  the  etiologic  factor  of 
tropical  dysentery. 

This    parasite    is    evidently   taken    into    the    system 


ANIMAL  PARASITES.  413 

in  polluted  water,  or  food  that  has  been  grown  on 
soil  fertilized  with  human  excrement.  The  preventive 
measures  which  are  most  serviceable  are  prompt  disin- 
fection of  all  stools  from  cases  of  chronic  d}'sentery,  fil- 
tration or  sterilization  of  infected  water-supplies,  and  the 
avoidance  of  raw  food  that  might  possibly  be  the  carrier 
of  the  infective  agents. 

Source  0/ the  Anieba  a?td  Mode  of  Infection. — Futcher^ 
states  that  "very  little  is  known  regarding  the  source 
of  the  ameba  and  the  mode  of  infection.  We  are  still 
absolutely  unfamiliar  with  the  life-history  of  the  para- 
site outside  of  the  body.  Inoculation  experiments  by 
way  of  the  mouth,  with  the  possible  exception  of  those 
of  Quincke  and  Roos  with  the  so-called  encysted  forms, 
have  been  entirely  negative.  It  is  highly  probable  that 
infection  takes  place  by  way  of  the  gastro-intestinal  tract, 
and  that  amebic  dysentery  is  contracted  in  much  the 
same  way  that  typhoid  fever,  cholera,  and  bacillary  dys- 
entery are  contracted." 

TJie  Plasmodium  of  Malaj'ia. — The  plasmodium  of 
malaria  belongs  in  the  order  Haemosporidia,  class  Spo- 
rozoa.  Three  different  parasites  are  recognized  :  the 
Plasmodium  malarise,  the  parasite  of  quartan,  Plasmo- 
dium vivax,  the  parasite  of  tertian,  and  Laverania  ma- 
larise, the  parasite  of  quotidian  fever.  Though  these 
three  parasites  differ  in  their  morphologic  and  biologic 
characters,  it  is  believed  that  each  of  them  finds  in  the 
Anopheles  its  appropriate  definitive  host  in  which  it  un- 
dergoes sexual  development  or  sporogony.  In  man  it 
undergoes  the  non-sexual  development,  or  schizogony. 

Trypanosomiasis. — The  occurrence  of  trypanosomes  in 
human  blood  was  first  reported  by  Button.^  The  preva- 
lent type  of  trypanosomiasis  infection  in  Africa  is  sleep- 
ing sickness.  The  parasite  most  commonly  found  in 
man  has  been  named  Trypanosoma  gambiense,  and  is  be- 
lieved to  differ  from  the  trypanosomes  producing  nagana, 
or  tsetse-fly  disease  of  horses,  occurring  in  Zululand  and 

1  Futcher,  yb«r.  Amer.  Med.  Assoc,  1903,  vol.  i.,  p.  480. 

2  Thojnpson-  Yates  Laboratory  Reports,  1902,  vol.  iv. 


414  VITAL  CAUSES  OF  DISEASE. 

South   and  West  Africa;    surra,  in   India;    dourin,  in 

Algiers  ;  mal  de  Caderas,  in  South  America ;  and  a  dis- 
ease of  cattle  recently  discovered  in  Pretoria.  The  ex- 
perimental evidence  at  hand  indicates  that  each  of  the 
parasites  producing  these  diseases  differs  in  certain  mor- 
phologic and  biologic  characters,  the  most  convincing  of 
which  is  the  lack  of  immunity  induced  by  one  parasite 
against  infection  by  another. 

During  the  past  year  a  second  type  of  trypanosome  in- 
fection in  man  has  been  discovered  in  different  parts  of 
Africa,  which  is  due  to  a  parasite  that  differs  morphologi- 
cally from  Trypanosoma  gambiense.  This  new  parasite 
has  been  named  Trypanosoma  rhodesiense.  It  causes  a 
form  of  sleeping  sickness  of  greater  virulence  than  that 
due  to  Trypanosoma  gambiense.  The  investigations  that 
have  been  made  indicate  that  Trypanosoma  rhodesiense 
is  disseminated  by  Glossina  morsitans  and  not  by  Glossina 
palpalis. 

A  third  trypanosome  has  recently  been  found  in  cases 
of  sleeping  sickness  in  Nigeria,  which  has  been  named 
Trypanosoma  nigeriense. 

Sleeping  sickness  is  stated  to  have  been  the  cause  of 
600,000  deaths  in  central  Africa  during  the  past  ten 
years,  and  hence  it  is  a  disease  of  great  importance  from 
a  public  health  standpoint,  especially  because  it  tends  to 
extend  to  new  territory  as  the  means  of  communication 
become  favorable. 

Whether  the  trypanosomes  of  sleeping  sickness  undergo 
some  form  of  development  in  the  body  of  the  fly,  or 
whether  the}'  are  transmitted  directly  by  means  of  the  in- 
fected proboscis,  cannot  be  stated  definitely,  but  the  gen- 
eral opinion  is  that  they  are  transmitted  most  commonly 
after  undergoing  transformation  in  the  body  of  the  fly. 

Glossina  morsitans  also  transmits  the  parasite  of  a 
trypanosomatic  infection  of  horses  and  wild  animals  in 
Africa — namely,  Tr3'panosoma  brucei — and  morphologi- 
cally the  parasite  resembles  that  of  sleeping  sickness. 
There  is,  however,  an  important  difference  between  the 


ANIMAL  PARASITES.  415 

parasites  in  that  Trypanosoma  briicei  and  Trypanosoma 
rhodesiense  are  easily  affected  by  human  blood-serum, 
while  Trypanosoma  gambiense  is  not.  Several  other 
forms  of  trypanosomatic  infection  occur  in  horses,  cattle, 
sheep,  dogs,  and  birds,  which  are  believed  to  be  trans- 
mitted by  blood-sucking  insects.  The  trypanosomatic 
infection  seen  in  rats,  due  to  infection  by  Trypanosoma 
lewisi,  is  believed  to  be  carried  from  diseased  to  healthy 
rats  by  fleas.  McNeal  has  also  found  that  Trypanosoma 
lewisi  is  transmitted  from  diseased  to  healthy  rats  by  in- 
fected lice.  L/ice  that  had  been  allowed  to  suck  the  blood 
of  infected  rats  had  the  parasites  in  their  stomachs  for 
some  time.  He  found  no  evidence  that  the  parasites  un- 
derwent transformation  in  the  lice. 

The  parasite  of  nagana,  Trypanosoma  brucei,  is  trans- 
mitted through  the  bite  of  the  tsetse-fly  (Glossina  morsi- 
tans) ;  the  parasite  of  dourin,  Trypanosoma  rongeti,  is 
transmitted  during  coition  ;  while  nothing  definite  is 
known  regarding  the  mode  of  transmission  of  Trypano- 
soma evansi,  the  parasite  of  surra  ;  Trypanosoma  elmas- 
siani,  the  parasite  of  mal  de  Caderas  ;  nor  of  Trypanosoma 
theileri,  the  parasite  occurring  in  cattle  in  Pretoria. 

Leishmainoses. — A  group  of  diseases  occurring  in  man 
in  the  Orient  is  due  to  a  parasite  known  under  the  name 
kala-azar  or  Oriental  boil.  This  parasite  was  first  dis- 
covered by  J.  B.  Leishman.  The  disease  is  due  to  a 
parasite  which  has  been  named  Leishmania  donovani, 
and  prevails  in  India  and  Ceylon.  Kala-azar  is  believed 
to  be  transmitted  by  a  flea,  Pulex  serraticeps. 

Piroplasmoses. — Diseases  in  which  the  red  blood-cor- 
puscles are  invaded  by  an  animal  parasite  which  differs 
materially  from  the  parasites  of  malaria  have  been  discov- 
ered in  cattle,  sheep,  dogs,  horses,  and  in  man.  Because 
of  the  peculiar  appearance  of  the  parasite  of  piroplas- 
moses, the  distinctive  name  has  been  coined  for  it.  In 
all  of  these  diseases  a  certain  type  of  tick  has  been  dis- 
covered to  be  the  transmitting  agent. 


4l6  VITAL   CAUSES  OF  DISEASE. 

Texas  Cattle  Fever. — Though  not  infectious  to  a  marked 
degree,  this  disease  has  an  important  relation  to  the  sub- 
ject under  discussion.  The  mode  of  transmission  of 
Texas  cattle  fever  is  of  a  type  entirely  different  from  that 
seen  in  any  of  the  diseases  discussed.  The  transmitting 
agent  in  this  disease  is  the  cattle  tick,  Boophilus  bovis, 
as  discovered  by  Theobald  Smith  in  1891.  This  insect 
is  believed  to  be  incapable  of  transmitting  the  disease 
directly.  The  fecundated  female  tick  sucks  the  blood  of 
infected  cattle  and  then  falls  to  the  ground  to  deposit  its 
eggs.  The  eggs  hatch  after  twenty  to  forty-five  days, 
and  the  young  ticks  attach  themselves  to  the  cattle  and 
carry  the  infection. 

It  will  be  seen  that  in  the  transmission  of  this  disease 
two  generations  of  ticks  are  requisite  to  complete  the 
cycle  of  development  of  the  parasite  and  permit  the 
dissemination  of  the  disease  from  infected  to  healthy 
cattle. 

Although  piroplasmoses  of  cattle  are  not  frequently 
transmitted  to  human  beings,  Lingard  has  found  the  Piro- 
plasma  bigeminus  in  a  herdsman  who  was  suffering  from 
malaria.  He  regards  it  as  probable  that  the  tick  is  capa- 
ble of  transmitting  the  parasite  of  cattle  fever  to  individ- 
uals that  are  otherwise  debilitated. 

Other  species  of  ticks  are  also  believed  to  be  instru- 
mental in  the  transmission  of  disease  among  sheep,  dogs, 
and  other  animals.  None  of  these  diseases  is,  however, 
infective  to  man,  so  far  as  known. 

Spotted  Fever  of  the  Rocky  Mountains. — This  disease  is 
localized  along  the  foothills  of  the  Rocky  Mountains  in 
Montana  and  Idaho.  It  is  believed  to  be  due  to  a  para- 
site localized  in  the  red  blood-corpuscles  of  human  beings, 
and  which  is  transmitted  by  means  of  a  tick,  Dermacentor 
occidentalis,  infesting  the  gopher.  While  certain  details 
of  the  nature  of  this  disease  and  the  mode  of  its  transmis- 
sion are  still  unsettled,  it  is  of  importance  in  this  partic- 
ular, because  the  evidence  seems  to  indicate  a  close  simi- 


ANIMAL  PARASITES.  417 

larity  in  the  form  of  the  parasite  and  in  the  mode  of  its 
transmission  to  that  seen  in  piroplasmoses  of  the  domestic 
animals. 

An  investigation  into  the  cause  of  the  so-called  "  spotted 
fever''''  of  the  Rocky  Mountains  by  Drs.  Wilson  and 
Chowning  ^  demonstrated  the  presence  of  an  animal  para- 
site in  the  blood  of  the  patients. 

Bacteriologic  examination  of  the  blood  and  tissues, 
of  persons  dying  of  the  disease  revealed  only  well- 
known  species  of  bacteria  normally  present  in  the  body. 
On  the  other  hand,  the  blood  was  found  to  contain  large 
numbers  of  a  parasite  somewhat  resembling  that  found 
in  Texas  fever  of  cattle,  although  it  is  larger  than  that, 
organism  and  possesses  ameboid  motion.  The  organism 
varies  greatly  in  form,  size,  and  staining  reaction  at 
various  stages  of  its  development.  The  smallest  forms 
are  from  i  to  2  ,«  in  size,  ovoidal  in  form,  and  possess  no 
ameboid  movement.  Another  phase  of  the  parasite  is 
usually  ovoidal  in  form,  from  3  to  5  //  in  size,  and  pos- 
sesses ameboid  movement.  In  freshly  drawn  blood  bodies 
are  sometimes  found  that  resemble  diplococci  which  are 
0.5  to  I  iJL  in  size  and  are  without  movement.  These 
forms  are  extracellular,  and  stain  faintly  with  methylene- 
blue. 

The  organism  of  "spotted  fever"  is  a  hematozo'ojt.,  and 
is  found  in  the  red  blood-cells  in  the  circulating  blood, 
but  more  plentifully  in  the  blood-cells  lying  in  the  con- 
gested capillaries  of  the  tissues.  The  fact  that  no  pig- 
ment was  found  in  the  organism  leads  the  discoverers  to- 
conclude  that  the  parasite  belongs  in  the  class  with  the 
Texas  fever  organism  and  not  with  the  malarial  group. 

Wilson  and  Chowning  believe  that  the  parasite  is  con- 
veyed to  man  by  the  bite  of  ticks,  several  species  of 
which  are  found  in  the  infected  locality.  Though  no 
infected  ticks  have  yet  been  encountered,  there  is  strong- 
presumptive  evidence  that  they  serve  as  the  carriers  of 

^  Jour.  Amer.  Med.  Assoc,  July  19,  1902. 
27 


41 8  VITAL    CAUSES  OF  DISEASE. 

the  parasite,  from  the  fact  that  the  disease  prevails  at  the 
season  of  the  year  when  the  ticks  are  prevalent — that  is, 
from  March  to  July. 

Inoculation  experiments  upon  rabbits  with  the  blood 
of  a  fatal  case  were  successful,  the  parasites  persisting  in 
the  blood  of  the  rabbit  for  four  weeks. 

The  discovery  of  a  hematozoon  in  the  blood  of  cases 
of  "spotted  fever"  has  been  confirmed  by  Dr.  John  F. 
Anderson." 

Other  Diseases  in  which  the  Occurrence  of  Animal 
Parasites  has  been  Reported. — The  most  important  dis- 
ease of  man  which  is  now  regarded  as  due  to  animal 
parasites  is  small-pox.  The  work  of  Councilman  and  his 
associates  presents  strong  evidence  in  favor  of  the  para- 
sitic theory  of  the  causation  of  small-pox.  Councilman 
believes  he  has  demonstrated  two  life-cycles  of  the  para- 
site, sexual  and  asexual,  the  former  occurring  only  in 
human  beings  and  in  monkeys,  while  the  latter  occurs  in 
man.,  as  well  as  in  the  lower  animals  (vaccinia).  These 
facts,  if  correct,  indicate  that  man  is  the  definitive  host 
of  the  small-pox  parasite,  and  that  cattle  serve  merely  as 
an  intermediate  host. 

Graham  2  presents  facts  which  indicate  that  the  etio- 
logic  factor  of  dengue  is  also  an  animal  parasite. 
Graham  believes  that  the  parasite  of  dengue  is  trans- 
mitted by  a  species  of  mosquito — Culex  fatigans.  He 
states  that  mosquitoes  that  had  bitten  a  sick  person  were 
carried  into  a  locality  where  there  was  no  case  of  dengue; 
two  persons  bitten  by  them  contracted  the  disease  after 
the  normal  incubation  period  of  four  to  five  days  respec- 
tively; no  new  cases  occurred  subsequently  in  the  village. 
The  role  of  the  mosquito  in  the  propagation  of  dengue 
appears  to  accord  with  these  facts. 

Naturally  Graham  has  sought  hematozoa  in  the  blood 
of  the  sick.     He  discovered  an  endoglobular  hematozoon 

1  Bulletin  No.  14,  Hygienic  Laboratory,  Public  Health  and  Marine  Hos- 
pital Service  of  the  United  States,  July,  1903. 

2  Journal  of  Tropical  Medicine,  1903,  vol.  vi. 


ANIMAL  PARASITES.  419 

with  ameboid  movements  which  he  found  constantly  in 
blood  taken  from  individuals  attacked  by  a  typical  form, 
and  where  the  temperature  was  above  38°  C.  (100°  F.). 
Graham's  description  of  the  parasite  is  made  solely  after 
examinations  in  the  fresh  state  ;  he  did  not  succeed  with 
stained  preparations. 

Graham  endeavored  to  follow  the  evolution  of  his 
Piroplasma  in  the  blood  of  mosquitoes  ;  he  found  that  it 
produced  spores,  and  very  soon  the  walls  of  the  stomach 
and  the  salivary  glands  contained  spores.  Mrs.  Graham 
was  attacked  with  dengue  the  third  day  after  having 
been  bitten  accidentally  by  one  of  these  mosquitoes. 

A  person  inoculated  with  an  emulsion  of  salivary 
glands  from  the  same  mosquitoes  had,  three  days  later, 
a  particularly  intense  attack  of  dengue. 

Helminthiasis. — Infection  by  different  kinds  of  worms 
is  of  less  hygienic  interest,  since  most  of  them  occur  in 
more  or  less  isolated  localities,  or  are  less  generally  dis- 
tributed than  some  of  the  sporozoa. 

The  larvae  of  the  trematodes  live  in  water  and  gain 
access  to  food.  They  are  also  disseminated  by  green 
vegetables  grown  on  soil  that  has  been  fertilized  with 
night-soil.  Of  the  nematodes,  the  larvae  of  Uncinaria 
and  Anguillula  are  disseminated  in  a  similar  manner. 
The  larvae  of  Filaria  medinensis  live  in  Cyclops  quadri- 
cornis,  which  is  so  common  in  fresh  water.  It  has  been 
determined  by  Manson  that  the  developmental  cycle  of 
Filaria  medinensis  in  the  body  of  Cyclops  requires  from 
five  to  nine  weeks,  and  the  cycle  in  the  human  being  is 
completed  by  the  next  year,  when  the  young  cyclops  is 
again  at  hand  to  serve  as  the  intermediate  host  of  the 
parasite. 

The  mosquito,  probably  both  Culex  and  Anopheles, 
serves  as  the  intermediate  host  of  Filaria  nocturna.  The 
embryos  of  the  parasite,  after  reaching  the  stomach  of 
the  mosquito,  penetrate  into  the  musculature  of  the 
thorax,   and    thence,  after   undergoing   further   develop- 


420 


VITAL  CAUSES  OF  DISEASE. 


ment,  they  pass  into  the  root  of  the  proboscis.  When 
they  reach  this  point,  they  are  injected  into  the  tissues 
of  the  person  in  the  act  of  sucking  blood. 

The  table  here  given,  taken  from  the  paper  of  Dr. 
Henry  B.  Ward,^  lists  all  the  human  parasites  of  the  va- 
rious groups  of  worms  heretofore  recorded,  and  is  based 
largely  on  the  classification  given  by  Braun. 


Found  as  Human  Parasite  in 

Type  of 
Parasitism. 

Recorded 
frequency 
as  human 
parasite. 

Parasite. 

Stage  of 
Parasite. 

Organ  of  Host. 

Trematoda  (flukes)  — 

Gastrodiscus  hominis 

Fasciola  hepatica 

Fasciola  angusta 

Fasciolopsis  buski 

Fasciolopsis  rathouisi 

Paragonimus  westermanii  .    .    . 
Opisthorchis  felineus   .    . 

Opisthorchis  sinensis 

Opisthorchis  noverca 

Metorchis  truncatus 

Heterophyes  heterophyes  .    .    . 
Dicrocoelium  lanceatum      .    . 
Schistosoma  hsematobium     .    . 

Adult 

Colon 
I.iver 

T               •     (■) 

Intestine 

Lung 
Liver 

Intestine 
Liver 
Portal  vein 

Occasional 

(?) 
Normal 
Occasional 
Normal 

Occasional  (?) 

Occasional 

Normal 

Occasional 

Normal 

Twice 

Rare 

Once 

Rare 

Once 

Abundant 

Frequent 

Once 

"     (?) 
Frequent 
Rare 
Frequent 

?  Record  open  to  question. 

The  occurrence  and  distribution  of  the  different  forms 
of  intestinal  parasites  in  the  United  States  are  far  more 
general  than  has  heretofore  been  believed.  The  marked 
prevalence  of  different  forms  of  intestinal  parasites  in 
those  exposed  to  infection  in  the  tropics  is  shown  by 
the  following  report  : 

In  Bulletin  No.  13  of  the  Hygienic  Laboratory  of  the 
Public  Health  and  Marine-Hospital  Service  there  was 
reported  a  statistical  study  of  the  intestinal  parasites  of 
500  white  male  patients  at  the  United  States  Govern- 
ment's Hospital  for  the  Insane.  A  summary  of  the 
results  obtained  in  this  study  shows  : 

I.  That  13.2  per  cent,  of  the  patients  examined  were 
infected  with  intestinal  parasites.  The  parasites  found 
were  hook-worms  (Uncinaria  Americana  or  Anchylos- 
toma  duodenale),  whip-worms  (Trichuris  trichiura),  seat- 

^Jour.  Amer.  Med.  Assoc,  September  19,  1903. 


ANIMAL  PARASITES. 


421 


Cestoda  (tape- worms)  — 

Dibothriocephalus  latus  .... 

Dibothriocephalus  cordatus  .    . 

Diplogonoporus  grandis         .    . 

Bothriocephalus  mansoni    .    .    . 

Dipylidium  caninum 

Hymenolepis  nana 

Hymenolepis  diminuta    .    .    .    . 

Hymenolepis  lanceolata  .  . 

Davainea  madagascanensis  .    . 

DavaineaC?)  asiatica    .        ,    .    . 

Tsnia  solium 

Cysticercus  cellulosae  .... 

Taenia  saginata  ....... 

Tsenia  marginata  ...... 

Tsenia  serrata     ...... 

Taenia  africana 

Taenia  confusa 

Taenia  echinococcus  (Echino- 
coccus  polymorphus)        .    .    . 

Taenia  hominis 

Nematoda  (round-worms)  — 

Leptodera  pellio 

Leptodera  niellyi 

Anguillula  aceti 

Strongyloides  stercoralis     .   .    . 

Gnathostoma  siamense    .... 

Filaria  medinensis 

Filaria  loa 

Filaria  volvulus      

Filaria  conjunctivae 

Filaria  lentis 

Filaria  restiformis 

Filaria  hominis  oris 

Filaria  labialis 

Filaria  lymphatica 

Filaria  immitis 

Filaria  bancrofti X 

Filaria  magalhaesi \ 

Filaria  perstans \ 

Filaria  diurna 

Filaria  demarquayi 

Filaria  romanorum  orientalis 

Filaria  ozzardi \ 

Filaria  kilimarae 

Trichuris  trichiura 

Trichinella  spiralis \ 

Strongylus  apri 

Strongylus  subtilis 

Dioctophyme  renale         .... 

Uncinaria  duodenalis  .    .    .    .  \ 

Uncinaria  americana 

Physaloptera  caucasica  .... 

Ascaris  lumbricoides 

Ascaris  canis 

Ascaris  maritima 

Oxyuris  vermicularis 

Gigantorhynchus  gigas  .... 
Gigantorhynchus  moniliformis 
Echinorhynchus  hominis    .    .    . 


Found  as  Human  Parasite  in 


pirf^i,°/       O'-gan  of  Host. 


Parasite. 


Larva 
Adult 


Larva 
Adult 
Larva 

Adult 


Larva 

Adult 

Adult 
Larva 
Adult 


Young 
Adult 

(?) 

(?) 
Adult 

(?) 
Adult 
Larva 
Adult 
Larva 
Adult 
Larva 


Adult 
Adult  (?) 
Larva 
Adult 


Larva 

Adult 


Larva 
Adult 


(?) 


Intestine 


Connective  tissue 
Intestine 


Connective  tissue 
Intestine 
Connective  tissue 
Intestine 


Connective  tissue 
Intestine 

Vagina 

Skin 

Bladder 

Intestine 

Skin 

Eye 

Lymph-vessels 
Conjunctiva 
Eye 

Bladder(?) 

Lip 
Lymph-vessels 

Lymph-vessels 

Blood 

Heart 

Blood 

Connective  tissue 

Blood 


Connective  tissue 

Blood 

Body  cavity 

Colon 

Intestine 

Muscle, 

Lung 

Stomach 

Kidney 

Intestine 

Connective  tissue 

Intestine 


T  •     (-^ 

Intestme 


Type  of 
Parasitism. 


Normal 
Occasional 


Normal  (?) 
Occasional 


(?) 
Normal 
Occasional 
Normal 

^        (■) 
Occasional 

Normal(?) 
(?) 

Normal 
"      (?) 

Accidental 

Accidental(?) 

Accidental 

Normal 

Occasional 

Normal 

r.  (•>       , 

Occasional 
(?) 

(?) 
(?) 

Occasional(?) 

(?) 
Normal 

Normal  (?) 

"       (?) 

Normal 
Normal(?) 
(?) 

Normal(?) 

(?) 
Normal 


Occasional 
Normal(?) 
Occasional 
Normal 


(?) 
Normal 
Occasional 

(?) 
Normal 
Occasional 

(?) 


Recorded 
frequency 
as  human 
parasite 


Abundant 
Rare 


Frequent 

Rare 

Once 

Rare 

Once 

Abundant 

Rare 

Abundant 

Once(?) 

Twice(?) 

Once 

Twice 

Frequent 
Once 

Once 

Rare 

Abundant 

Once 

Abundant 

Frequent 

Rare 

Uncertain 
Once 


Twice 

Uncertain 

Abundant 

Frequent 

Rare 

Once 

Frequent 

Rare 

Once 

Rare 
Once 
Abundant 


Rare 

Twice 

Rare 

Abundant 


Once 

Abundant 

Rare 

Once 

Abundant 

Rare 

Once 


Record  open  to  question. 


422  VITAL  CAUSES  OF  DISEASE. 

worms  (Oxyuris  vermicularis) ,  Cochin-China  worms 
(Strongyloides  stercoralis),  eel-worms  (Ascaris  lumbri- 
coides).  No  evidence  of  infection  with  tape-worms, 
flukes,   or  coccidia  was  found. 

2.  The  results  obtained  differ  from  those  of  most  for- 
eign investigators  principally  in  the  lower  rate  of  infec- 
tion, in  the  absence  of  tape-worms,  and  in  the  presence 
of  hook-worms  and  of  the  Cochin-China  worms. 

3.  The  results  show  that  the  percentage  of  infection 
tends  to  vary  inversely  with  the  age  and  with  the  dura- 
tion of  institutional  life  of  the  patients. 

4.  They  also  indicate  that  army  life  is  conducive  to 
parasitic  infection  of  the  intestine,  and,  moreover,  that 
a  high  percentage  of  the  United  States  soldiers  returning 
from  service  in  the  Philippine  Islands  have  intestinal 
parasites. 

5.  The  presence  of  a  moderate  number  of  worms  in 
the  intestine  has  no  relation  to  the  presence  of  undi- 
gested starch  and  meat  in  the  dejecta  or  to  the  litmus 
reaction  of  the  feces. 

Frequency  of  Infection. — Of  the  500  patients  exam- 
ined, 66  patients,  or  13.2  per  cent,  showed  parasitic 
infection  of  the  intestines  ;  10  patients  had  a  double  in- 
fection, and  in  one  case  three  different  parasites  were 
present,  making  a  total  of  78  infections.  These  were 
distributed  among  five  parasites  as  follows : 

Uncinaria  Americana,  or  Anchylostoma  duodenale 
(hook-worms),  15  cases,  or  3  per  cent,  of  the  cases  exam- 
ined. 

Trichuris  trichiura  (whip-worms),  54  cases,  or  10.8 
per  cent. 

Oxyuris  vermicularis  (vSeat- worms),  4  cases,  or  0.8  per 
cent. 

Strongyloides  stercoralis  (Cochin-China  worms),  3 
cases,  or  0.6  per  cent. 

Ascaris  lumbricoides  (eel- worms),  2  cases,  or  0.4  per 
cent. 


PREVENTION  OF  INFECTION  WITH  ANIMALS.   423 

The  Hook-worm  Disease  {Uncinariasis) . — Stiles  ^  states 
that — "This  is  a  newly  recognized  factor  in  anemias  in 
America.  In  traveling  from  Virginia  to  Florida,  as  we 
go  south  anemia  increases.  The  cases  may  be  divided 
into  two  general  classes,  one  due  to  malarial  infection 
and  the  other  to  the  Uncinaria  Americana.  The  former 
is  especially  prevalent  where  the  soils  are  impervious, 
and  the  latter  occurs  in  the  sandy  areas.  At  Waycross, 
in  southeastern  Georgia,  there  are  about  twenty  cases 
of  hook-worm  disease  to  one  case  of  malaria. 

"The  hook-worm  disease  of  Europe  is  due  to  the 
Uncinaria  duodenalis,  while  the  American  disease  is 
caused  by  another  species  of  the  same  parasite,  known 
as  the  Uncinaria  Americana.  The  parasites  live  in  the 
small  intestine  and  suck  the  blood.  One  factor  in  the 
production  of  the  disease  is  the  loss  of  blood  taken  by 
the  parasite.  In  addition,  minute  hemorrhages  occur 
from  the  wounds  made  by  the  worms.  These  wounds 
may  ulcerate.  The  intestinal  walls  are  thickened,  and 
their  digestive  surface  is  decreased.  The  parasites  appa- 
rently produce  a  poisonous  substance.  All  these  factors 
are  involved  in  the  symptoms  of  the  disorder." 

Trichinosis. — The  Trichinella  spiralis  is  ingested 
through  the  use  of  raw  meat,  more  particularly  raw 
pork,  though  among  the  flesh-yielding  domestic  ani- 
mals, calves  and  sheep  may  also  be  infected.  Rats, 
cats,  and  hogs  serve  as  intermediate  hosts  of  the  para- 
site. 

The  thorough  cooking  of  all  meat  will  be  a  positive 
safeguard  against  infection  from  this  parasite,  as  it  is 
destroyed  when  heated  above  65°  C.  for  several  minutes. 
Complete  drying  also  destroys  the  parasite,  and  pickling 
the  meat  serves  to  kill  the  parasite  in  a  few  months. 

Prevention  of  Infection  with.  Animal  Parasites. — 
In  a  paper  presented  to  the  International  Congress  of 
Hygiene  (1891,  vol.  i).  Dr.  Prospero  Sonsino  gives 
succinct  directions  for  preventing  this  form  of  infection: 

^Brooklyn  Medical  Journal,  1903,  vol.  xvii.,  p.  51. 


424  VITAL  CAUSES  OF  DISEASE. 

"  I.  Pure  spring-water,  or  else  boiled  or  filtered  water, 
alone  are  to  be  drunk.  Drinking-water  is  to  be  preserved 
in  good  and  well-covered  vessels.  River-  or  lake-water 
not  to  be  imbibed  while  bathing.  This  rule  regards  pre- 
vention especially  from  Bilharzia  haematobia,  Filaria  san- 
guinis hominis,  Ranunculus  medinensis,  Rhabdonema  in- 
testinale,  and  probably  from  Filaria  loa  and  many  others. 
The  relatively  large  dimensions  of  the  eggs  and  larval 
stage  of  entozoa  hinder  their  passage  with  drinking- 
water  through  a  good  filter;  therefore  proper  filtration 
of  drinking-water  suffices. 

' '  2.  Meat,  fresh- water  fish,  and  vegetables  are  to  be  well 
cooked  and  kept  from  insects  (flies).  For  children  and 
invalids,  raw  meat  can  be  used,  provided  that  it  is  well 
pounded  and  passed  through  a  suitable  sieve.  This  rule 
regards  prevention  especially  from  Trichina  spiralis. 
Taenia  solium,  T.  saginata  (mediocanellata),  Bothrio- 
cephalus  latus,  Ascaris  lumbricoides,  A.  mystax,  Dis- 
toma  lanceolatum,  Fasciola  hepatica,  and  others.  The 
modern  use  of  raw  beef  for  children  and  invalids  has 
been  the  cause  of  an  extraordinary  spread  of  Taenia 
saginata. 

' '  Depraved  tastes  for  substances  not  possessed  of  ali- 
mentary qualities  (pica  and  geophagia)  are  not  to  be  yielded 
to.  This  rule  regards  the  preventioii  from  Taenia  nana, 
leptocephalia,  canina,  and  probably  from  Distoma  hetero- 
phyes,  Echinorhynchus  hominis,  Ascaris  lumbricoides, 
A.  mystax.  Many  of  these  entozoa  have,  or  are  sus- 
pected to  have,  insects  as  intermediary  hosts,  which  may 
be  conveyed  to  the  stomach  of  man  through  the  habit  of 
those  affected  with  pica  and  geophagia  of  eating  dirty 
things. 

' '  4.  Special  forms  of  food  in  use  by  the  natives  of 
countries  possessing  special  entozoa  are  to  be  avoided,  or 
only  taken  after  thorough  cooking.  This  rule  is  calcu- 
lated to  prevent  Bothriocephalus  cordatus,  B.  Mansoni, 
Distoma  crassum,  D.  heterophyes,  D.  sinense,  and  D. 
Rinoferi. 


VEGETABLE  PARASITES.  425 

"5.  Hands  and  nails  are  to  be  kept  thoroughly  clean, 

particularly  when  about  to  eat.  Domestic  animals  are  to 
be  handled  with  caution — dogs  especially.  Caution  in 
handling  entozoa;  their  speedy  and  complete  destruction 
by  fire  whenever  it  is  not  necessary  to  preserve  them  for 
medical  purposes.  This  rule  is  of  great  importance, 
especially  for  preserving  man  from  Anchylostoma  duod- 
enale,  echinococcus,  Pentastoma  denticulatum,  Taenia 
canina,  T.  solium,  and  Oxyuris  vermicularis. 

"  6.  The  body  is  to  be  kept  free  from  epizoa  (mosqui- 
toes, bugs,  fleas,  etc.).  This  rule  is  of  great  importance 
in  guarding  against  some  of  the  above-mentioned  worms, 
so  as  to  interfere  with  the  life-cycle  of  those  parasites,  as 
well  as  with  that  of  several  of  the  filariae." 

It  is  safe  to  assume  that  protection  against  epizoa  will 
be  of  value  in  preventing  infection  from  a  number  of 
other  diseases  the  specific  causes  of  which  are  as  yet  un- 
determined. Our  knowledge  with  reg-ard  to  the  dis- 
semination  of  disease  by  means  of  insects  has  been  care- 
fully summarized  by  Nuttall.^ 

Vegetable  Parasites. — The  vegetable  parasites  are 
less  formidable  in  their  action  than  the  animal  parasites. 
The  diseases  due  to  the  vegetable  parasites  are  usually 
slow  in  development  and  less  destructive  in  their  action. 

The  Trichophyton  fiitigiis  is  a  common  parasite  among 
the  poorer  classes.  The  diseases  produced  by  it  are 
known  as  tinea  circinata,  tonsurans,  and  sycosis,  accord- 
ing to  the  location  of  the  disease.  Cleanliness  and  sim- 
ple antiseptic  treatment  serve  to  eradicate  the  disease. 

The  ATicrosporon  fiirfiir  produces  the  disease  known 
as  tinea  versicolor,  and  is  but  slightly  contagious.  The 
Achorion  Schonleinii  produces  the  disease  known  as 
tinea  favosa,  which  is  distinctly  contagious  in  character 
and  difficult  to  eradicate.  The  Microsporon  minutissi- 
mum  produces  the  disease  known  as  erythrasma,  which 
is  similar  in  many  respects  to  tinea  versicolor. 

Actinomycosis  is  a  disease  due  to  an  organism  which  is 

^  Hygienische  Rundschau,  Jahr.  9.,  1899. 


426  VITAL  CAUSES  OF  DISEASE. 

regarded  as  being  higher  in  the  scale  of  the  vegetable 
kingdom  than  the  bacteria,  and  may  be  briefly  considered 
here.  A  considerable  group  of  organisms  has  been  dis- 
covered which  have  some  of  the  characters  of  the  ray 
fungus,  among  which  are  the  Bacillus  tuberculosis  and 
the  related  "acid-fast"  organisms  found  in  butter,  hay, 
and  grass.  This  whole  group  of  organisms,  including 
the  Bacillus  tuberculosis,  is  now  classed  together  under 
the  name  actinomycetes. 

The  Actinomycis  bovis,  or  ray  fungus,  affects  man  as 
well  as  animals.  It  is  believed  to  gain  entrance  to  the 
body  through  carious  teeth.  It  produces  deep  subcuta- 
neous swellings  or  tumors,  which  finally  break  down 
and  suppurate,  discharging  a  thin,  bloody  sero-pus  con- 
taining characteristic  yellow  granules. 

The  disease  often  yields  to  the  administration  of  large 
doses  of  potassium  iodid. 

Actinomyces  madurse  is  a  vegetable  parasite  which  is 
the  cause  of  an  endemic  disease  known  as  Madura  foot, 
and  which  is  characterized  by  disintegration  of  the  tis- 
sues, chiefly  of  the  foot  and  hand.  The  disease  occurs 
most  frequently  in  India,  though  Wright  encountered  a 
case  in  Boston.  The  disease  pursues  a  chronic  course, 
and  the  only  successful  treatment  is  by  means  of  the 
knife  or  curet. 

O'idioinycosis. — Ricketts^  has  collected  a  number  of 
cases  of  disease  of  the  skin  which  were  traced  to  organ- 
isms belonging  to  the  genus  Oidium.  The  variations 
among  the  organisms  represented  three  morphologic 
types  :  (i)  Blastomycetoid  or  yeast-like  ;  (2)  oidium-like  ; 
(3)  hyphomycetoid. 

The  Oidium  albicaiis  is  the  organism  which  produces 
thrush,  a  disease  of  the  mucous  membranes  in  enfeebled 
infants. 

The  Oidium  lactis  is  found  in  sour  milk,  on  bread  and 
decayed  fruit,  and,  so  far  as  known,  is  non-pathogenic. 
It  is  frequently  encountered  in  the  mouth. 

^  Jour,  of  Med.  Research,  1901,  vol.  vi. 


VEGETABLE  PARASITES.  427 

Sporotrichosis. — According  to  Ruediger^  57  cases  of 
sporotrichosis  have  been  reported  in  the  United  States, 
50  cases  in  France,  and  i  or  2  in  Germany.  Of  the 
cases  reported  in  the  United  States  five-sixths  of  the  total 
of  57  cases  have  been  observed  in  the-  valley  of  the 
^lissouri  River,  the  remaining  10  cases  being  widely 
scattered  from  the  i\tlantic  to  the  Pacific  coast.  Ruediger 
believes  that  the  parasite  lives  as  a  saprophyte  on  grains, 
grasses,  or  other  vegetation,  as  the  disease  is  seen  most 
frequently  among  farm  laborers  ;  but  there  is  no  direct 
evidence  that  the  infection  in  man  is  contracted  from 
horses. 

1  Jour,  of  Infectious  Diseases,  vol.  xi.,  p.  193. 


CHAPTER   XVIII. 
DISINFECTION. 

Aside  from  the  prophylactic  measures  already  spoken 
of,  there  are  other  measures  in  common  use  to  limit  the 
spreading  of  the  infectious  diseases.  These  measures  are 
employed  to  destroy  the  specific  bacteria  and  other  in- 
fective agents  outside  the  body.  These  measures  are 
commonly  included  under  the  broad  term  disinfection. 
To  disinfect  is  to  render  non-infective,  and  a  disinfectant 
is,  therefore,  any  agent  that  is  capable  of  destroying  infec- 
tive materials  or  of  rendering  them  inert.  Chemical  sub- 
stances which  in  certain  definite  proportions  kill  bacteria 
in  fluids,  and  when  present  in  smaller  amounts  prevent 
their  multiplication,  are  disinfectants.  When  present  in 
the  larger  amounts  they  act  as  germicides — that  is,  they 
kill  the  bacteria;  while  in  the  smaller  amounts  they  are 
simply  disinfectants,  because  they  render  the  bacteria 
incapable  of  multiplication.  The  term  disinfectant  is 
also  sometimes  applied  to  substances  which  destroy  bad 
odors.  This  is,  however,  an  improper  use  of  the  term 
disinfectant.  These  substances  which  destroy  bad  odors 
are  deodorants,  and  may  or  may  not  be  disinfectants. 
Substances  which  retard  or  prevent  the  growth  of  bacteria 
are  usually  spoken  of  as  antiseptics,  because  they  prevent 
the  growth  of  the  septic  bacteria  as  well  as  others.  These 
antiseptic  substances,  in  larger  amounts,  generally  are 
germicides. 

A  reliable  disinfecting  agent  is,  therefore,  one  that  is 
germicidal  in  its  action.  A  good  disinfectant  should, 
however,  be  as  free  as  possible  from  poisonous  action 
upon  those  who  use  it,  and,  at  the  same  time,  it  should 
not   be  destructive    to    the    articles    to   be  disinfected. 

428 


DISINFECTION.  429 

The  latter  quality  is  a  most  important  one  from  the  fact 
that  a  number  of  very  useful  disinfecting  agents  have  an 
injurious  or  even  destructive  action  upon  the  articles  to 
be  disinfected.  For  this  reason  dry  heat  is  not  applicable 
to  the  disinfection  of  fabrics,  because  the  degree  of  heat 
required  to  disinfect  thoroughly  would  be  sufficient  to 
char  them.  Articles  of  clothing  containing  blood  or 
other  stains  should  not  be  disinfected  by  means  of  hot 
water  or  steam,  because  these  agents  fix  the  stains  so  that 
they  remain  permanent.  Many  of  the  other  disinfecting 
agents  have  a  corrosive  action  upon  metals,  and  are, 
therefore,  not  adapted  for  the  disinfection  of  metallic 
articles.  Consequently  it  is  necessary  to  select  that  dis- 
infecting agent  which  is  least  likely  to  prove  objection- 
able. Fortunately  we  have  a  rather  wide  range  of  sub- 
stances and  agencies  to  select  from  according  to  the 
nature  of  the  articles  to  be  disinfected. 

The  disinfecting  agent  should  be  cheap,  in  order  to 
lessen  the  expense  as  much  as  possible.  Here  again  it  is 
possible  to  select,  for  certain  purposes,  agents  that  are 
comparatively  cheap  and  yet  quite  efficient.  Under 
other  circumstances  it  is  not  possible  to  avail  ourselves 
of  the  cheapest  agents,  because  they  are  not  suitable  for 
other  reasons.  For  instance,  milk  of  lime  is  a  most 
excellent  disinfectant  for  rough  work,  but  it  would  not 
be  applicable  under  all  conditions. 

All  our  present  knowledge  of  the  value  and  eflSciency 
of  the  different  disinfecting  agents  is  based  upon  labora- 
tory experiments,  and  it  is  only  since  the  evolution  of 
modern  bacteriology  and  the  perfection  of  bacteriologic 
methods  that  it  was  possible  to  give  intelligent  direction 
to  our  efforts  toward  the  limitation  and  eradication  of 
disease  by  such  means. 

Some  sanitarians  have  regarded  the  terminal  disin- 
fection of  infected  houses  as  valueless,  and  claim  that  by 
proper  attention  to  the  handling  of  the  patient  and  his 
excreta  terminal  disinfection  could  be  omitted.  WTiile 
others  grant  that  it  is  possible  through  intelHgent  over- 
sight  to   prevent   the   dissemination   of   the   infecting 


430  DISINFECTION. 

bacteria,  it  is,  however,  certain  that  the  necessary 
precautions  are  not  exercised,  and  hence  it  is  unsafe  to 
omit  terminal  disinfection. 

Disinfectants  in  Common  Use. — The  disinfectants  in 
common  use  are  of  two  classes,  heat  and  chemical  sub- 
stances. Heat  may  be  employed  as  a  disinfectant  in 
several  different  ways — as  dry  heat,  150°  to  175°  C,  for 
one  to  two  hours;  or  as  moist  heat,  as  steam  or  boiling 
water.  The  principal  chemical  disinfectants  are  formal- 
dehyd  gas  and  solution,  mercuric  chlorid  solution,  car- 
bolic acid  solution,  trikresol,  chlorid  of  lime  and  caustic 
lime,  sulphur  dioxid,  zinc  chlorid,  and  copper  sulphate. 
Fire  is  also  a  most  efficient  disinfectant,  but  is  applicable 
only  for  substances  that  are  not  combustible,  or  for  com- 
bustible substances  that  are  of  little  or  no  value.  Sun- 
light is  also  an  efficient  disinfectant.  This  agent  is  con- 
stantly acting  and,  no  doubt,  removes  most  of  the  detri- 
mental agents  on  surfaces  exposed  to  the  sun.  Most 
bacteria  grow  best  in  the  dark.  Many  species  fail  to 
grow  at  all  in  diffiise  daylight,  while  direct  sunlight  is 
injurious  to  all  species. 

The  Action  of  Sunlight  Upon  Bacteria,  With  Spe- 
cial Reference  to  Bacillus  Tuberculosis.— J.  Weinz- 
irl  ^  made  a  study  of  the  various  methods  which  have 
been  used  in  determining  the  effect  of  sunlight  upon  bac- 
teria. Objections  are  found  to  most  of  these  methods  in 
that  they  do  not  constitute  true  exposures,  the  bacteria 
beinsf  covered  with  grlass  or  other  material  which  absorbs 
and  reflects  some  of  the  sun's  rays.  When  bacteria  were 
directly  exposed  to  the  rays  of  the  sun  without  any  cover- 
ing over  them,  the  author  found  that  the  germicidal  action 
of  sunlight  was  much  more  effective  than  it  had  previously 
been  considered. 

The  organisms  upon  which  observations  were  made 
were  the  bacilli  of  tuberculosis,  typhoid  fever,  cholera, 
diphtheria,  etc.,  but  particular  attention  was  given  to  the 
tubercle  bacillus.     It  was  found  that  this  organism,   as 

^  Jour.  Inject.  Diseases,  May,  1907,  Sup.  3,  pp.  128-153,  pls.  2. 


DISINFECTION  ON  LARGE  SCALE.  431 

well  as  other  pathogenic  non-spore-bearing  bacteria,  is 
destroyed  in  from  two  to  ten  minutes  by  direct  exposure  to 
sunlight.  According  to  the  author,  the  hygienic  impor- 
tance of  sunlight  has  been  considerably  underestimated 
and  nonspore-bearing  bacteria,  when  freely  exposed,  are 
killed  in  from  one-fifth  to  one-twentieth  of  the  time  previ- 
ously considered  necessary. 

Disinfection   on   I/arge    Scale. — Disinfection   on   a 


Fig.  60. — Steam  disinfecting  plant. 

large  scale,  for  infected  clothing  and  bedding,  is  usually 
accomplished  by  means  of  steam  under  pressure.  A 
special  form  of  apparatus  is  required  for  this  purpose 
(see  Fig.  60).  A  special  building  should  be  constructed 
for  a  municipal  disinfecting  plant.  The  disinfecting 
chamber  should  be  so  arranged  that  the  infected  clothing 
is  brousfht  into  one  room,  where  it  is  introduced  into  the 
disinfecting  chamber.     After  it  has  been  disinfected,  it  is 


432  DISINFECTION. 

taken  out  of  the  chamber  from  the  other  side  of  a  parti- 
tion wall  and  stored  in  a  room  that  has  no  connection 
with  the  first  room  except  through  the  disinfecting 
chamber.  The  doors  of  the  disinfecting  chamber  should 
be  so  arranged  that  only  one  can  be  opened  at  a  time,  so 
as  to  prevent  infectious  materials  from  being  carried  over 
into  the  room  containing  the  disinfected  clothing.  The 
attendants  handling  the  infected  clothing  should  not 
come  in  contact  with  those  who  handle  the  disinfected 
clothing.  The  disinfected  clothing  should  never  be  re- 
turned in  the  same  conveyance  used  for  the  collection  of 
infected  clothing. 

The  disinfecting  power  of  steam  is  dependent  upon 
the  extent  of  the  pressure  to  which  it  is  subjected, 
the  greater  the  pressure  the  higher  its  disinfecting 
power,  because  the  temperature  of  the  steam  increases 
with  the  increased  pressure.  The  steam  given  off 
from  boiling  water  in  an  open  vessel  has  the  same 
temperature  as  that  of  the  water — ioo°  C.  At  one 
additional  atmosphere  pressure  we  obtain  a  temperature 
of  121.5°  C;  at  two  atmospheres,  135°  C. ;  at  three  atmos- 
pheres, 145°  C;  at  four  atmospheres,  153.3°  C;  ^"^^  ^^ 
five  atmospheres,  160°  C.  A  pressure  of  one  atmosphere 
is  equal  to  i  kilogram  per  square  centimeter  of  surface. 
Spores  are  not  destroyed  when  heated  to  the  temperature 
of  boiling  water,  but  at  a  pressure  of  two  to  three  addi- 
tional atmospheres  disinfection  by  steam  kills  spores 
almost  immediately.  All  pathogenic  bacteria  in  the 
vegetative  stage  are  killed  when  heated  to  from  65°  to 
75°  C,  so  that  the  temperature  of  boiling  water  is  suf- 
ficient to  kill  a  large  number  of  the  different  species  of 
pathogenic  bacteria — the  non-spore-bearing  forms.  When 
infected  clothing  and  bedding  are  to  be  disinfected  by 
means  of  steam,  it  is  necessary  to  use  steam  under  press- 
ure to  cause  the  heat  to  penetrate  into  the  interior  of  the 
bundles  to  be  disinfected. 

Formaldehyd. — Of  the  diflferent  chemical  disinfect- 
ants, formaldehyd  is  now  considered  the  most  efficient, 
and  is  in  general  use  for  the  purpose  of  room  disinfection. 


GENERA  TION  OF  FORMALDEHYD  GAS.        433 

The  disinfectant  action  of  formaldehyd  was  discovered 
in  1886  by  O.  Loew.  The  formaldehyd  gas,  as  generally 
employed  for  purposes  of  disinfection,  has  no  great  pene- 
trating powers,  and  it  cannot,  therefore,  be  relied  upon  for 
the  disinfection  of  bundles  of  clothing  and  bedding.  For 
the  disinfection  of  such  articles  the  gas  must  be  applied 
under  pressure  by  means  of  a  vacuum  chamber.  This 
disinfectant  is  most  commonly  used  for  the  disinfection 
of  rooms  in  which  there  have  been  cases  of  infectious 
diseases.  It  is  entirely  harmless  for  all  classes  of  house- 
hold goods.  Upon  the  removal  of  the  patient  the  room 
is  closed  as  tightly  as  possible,  and  all  cracks  are  closed 
by  means  of  gummed  paper;  all  the  bedding  and  clothing 
are  spread  out,  the  drawers,  doors  of  cupboards,  and 
closets  are  opened,  and  the  gas  is  introduced  through  the 
keyhole  of  the  door.  The  gas  is  generated  in  a  special 
apparatus  outside  the  room,  either  from  an  aqueous  solu- 
tion of  the  gas  by  the  application  of  heat,  by  the  oxida- 
tion of  wood  alcohol,  or  by  the  volatilization  of  paraform 
by  means  of  heat. 

Generation  of  Formaldehyd  Gas. — An  excellent 
form  of  formaldehyd  gas  regenerator  is  that  manu- 
factured by  Lentz  &  Sons,  of  Philadelphia  (Fig.  61), 
which  consists  of  a  stout  copper  retort  of  about  2\  liters 
(4  pints)  capacity,  with  fannel  filling  tube  and  level 
indicator,  a  stopper  of  special  construction,  and  inclined 
brass  outlet  tube  of  large  bore,  connected  by  means  of  a 
flexible  tube  with  another  and  smaller  brass  tube,  which  is 
inserted  through  the  keyhole  of  the  room  to  be  disinfected. 

The  solution  in  the  retort  is  heated  by  means  of  a 
special  form  of  "Primus"  lamp,  D,  which  burns  kero- 
sene and  develops  a  temperature  of  1150°  C.  (2100°  F.). 
The  solution  is  introduced  into  the  bottom  of  the  retort 
through  the  small  funnel  at  the  top,  and  the  stopcock  A 
on  the  connection  is  allowed  to  remain  open,  so  that  ex- 
haustion of  the  solution  is  at  once  detected  by  the  escape 
of  gas.  The  cap  of  the  retort  is  held  in  position  by 
means  of  a  strong  iron  yoke,  provided  with  a  clamping 
screw,  B.     When  the  supply  of  solution  in  the  retort  is 

28 


434 


DISINFECTION. 


exhausted  the  flame  is  at  once  extinguished  by  turning 
the  thumb-screw  F  to  the  left.  If  it  is  desired  to  con- 
tinue the  disinfection,  a  filled  retort  can  be  substituted 
for  the  exhausted  one  by  turning  the  screw  C,  which 
holds  the  retort  in  place.  The  heat  of  the  flame  is  per- 
fectly under  the  control  of  the  operator.      It  can   be  in- 


FlG.  6i. — Formaldehyd  gas 
regenerator. 


Fig.  62. — Formaldehyd  gas 
regenerator. 


creased  by  means  of  the  pump  G,  or  decreased  by  means 
of  the  valve. 

The  efiiciency  of  this  apparatus  is  attested  by  the  fact 
that  the  United  States  War  Department  has  over  one 
hundred  of  them  in  use,  besides  large  numbers  in  use 
b)^  boards  of  health  in  many  of  the  larger  cities,  by  hos- 
pitals, schools,  and  physicians. 

Fig,  62  represents  the   Trenner-Lee  formaldehyd   re- 


GENERA  TION  OF  FORMALDEHYD  GAS.       435 

generator,  for  which  certain  important  advantages  are 
claimed.  It  is  so  constrncted  as  to  permit  its  use  either 
within  the  room  to  be  disinfected  or  outside  the  room.  The 
introduction  of  copper  j^lates  in  the  interior  of  the  retort 
serves  to  prevent  the  frothing  of  the  boiling  fluid,  and 
hence  prevents  the  projection  of  fluid  from  the  apparatus. 
The  use  of  a  large  alcohol  burner  makes  it  possible  to 
generate  the  gas  very  quickly,  rapidly,  and  uniformly, 
and  the  amount  of  alcohol  in  the  burner  can  be  so  regu- 
lated as  to  become  exhausted  and  extinguish  the  flame 
when  all  the  solution  has  been  utilized.  This  is  an  im- 
portant advantage  when  the  apparatus  is  to  be  placed  in 
the  room  to  be  disinfected. 

The  formaldehyd  gas  acts  most  efficiently  when  moist 
and  at  a  high  temperature.  To  meet  these  conditions 
the  gas  is  either  mixed  with  steam  or  it  is  generated  from 
a  mixture  of  formaldehyd  solution  and  glycerin.  The 
glycerin  prevents  the  gas  from  polymerizing  as  readily 
as  when  in  the  dry  state.  The  moisture  may  be  sup- 
plied also  by  spraying  all  the  surfaces  of  the  room,  as 
well  as  all  articles  contained  in  it,  with  a  solution  of 
formaldehyd  before  beginning  the  disinfection,  or  by 
suspending  sheets,  saturated  with  formaldehyd,  in  the 
room.  It  is  entirely  harmless  in  its  action  upon  fabrics, 
and  is  not  highly  poisonous,  though  it  has  an  irritant 
action  upon  the  mucous  membrane  when  respired.^  The 
formic  aldehyd  solution  contains  about  40  per  cent,  of 
the  gas,  and  is  relatively  cheap.  It  can  be  purchased 
everywhere  in  this  form,  and  is  also  sold,  at  a  much 
higher  price,  under  the  trade  name  of  ' '  formalin. ' '  From 
500  to  600  cubic  centimeters  of  the  glycerin-formaldehyd 
mixture  (i  :  50)  are  usually  employed  to  disinfect  a  space 
of  from  25  to  30  cubic  meters.  A  liter  of  wood  alcohol 
will  yield  748  grams  =  361  liters  of  aldehyd.  This 
amount  of  gas  in  a  room  of  25  to  30  cubic  meters  would 

1  Disinfection  by  means  of  formaldehyd  has  been  rendered  quite  safe,  with 
regard  to  danger  from  fire,  since  the  modern  apparatuses  permit  the  evolution 
of  the  gas  outside  the  room  to  be  disinfected,  the  gas  being  conducted  into  the 
room  through  the  key-hole. 


43^  DISINFECTION. 

give  1.25  to  1.5  per  cent,  of  aldehyd  in  the  air  of  the 
room.  Stiiver  concludes  that  a  closed  room  must  con- 
tain 2. 5  grams  of  formaldehyd  per  cubic  meter  of  space. 
1.6  grams  per  cubic  meter  kills  all  organisms  not  in  the 
spore  stage.  The  room  should  remain  closed  for  six 
hours  after  the  gas  has  been  generated. 

I^iquid  Formaldehyd  -  spraying.  —  The  Board  of 
Health  of  Philadelphia  has  for  some  years  abandoned 
formaldehyd  generators,  and  has  relied  solely  upon 
the  spraying  of  infected  rooms  with  formaldehyd  by 
means  of  a  large  spraying  apparatus.  There  is  no  doubt 
that  the  disinfection  of  houses  as  practised  to-day  is  not 
always  efficacious.  Disinfection  by  burning  sulphur  in  a 
room  is  almost  valueless  for  the  bacterial  infections,  since 
it  is  impossible  to  generate  sufficient  sulphur  dioxid  in 
this  manner  to  kill  the  pathogenic  organisms.  In  like 
manner  the  generation  of  formaldehyd  gas  by  the  dif- 
ferent methods  in  use  is  rarely  efficacious,  since  in  prac- 
tical experiments,  under  the  most  favorable  conditions 
that  can  be  improvised,  only  about  80  per  cent,  of  the 
test  objects  are  destroyed.  The  use  of  formaldehyd  in 
solution  by  means  of  a  large  spraying  apparatus  gives 
the  most  satisfactory  results,  as  by  this  means  it  is  possi- 
ble to  destroy  100  per  cent,  of  test  objects.  With  such 
an  efficient  method  of  disinfection  in  use  we  may  hope  to 
see  a  more  prompt  subsidence  of  outbreaks  of  the  trans- 
missible diseases  than  has  ever  been  the  case.  Moreover, 
this  method  of  disinfection  is  unattended  with  the  dangers 
of  fire  that  always  attend  the  older  methods.  Three  pints 
of  equal  parts  of  formaldehyd  (40  per  cent,  solution)  and 
water  is  sufficient  to  disinfect  a  room  having  1000  cubic 
feet  of  space.  This  solution  is  sprayed  over  the  bed- 
clothes, furniture,  walls,  floors,  etc.,  and  is  allowed  to 
act  for  twenty-four  hours,  after  which  the  room  may  be 
thoroughly  aired. 

Sulphur  Dioxid. — Sulphur  dioxid  was  formerly  em- 
ployed to  a  large  extent  for  the  purposes  for  which  for- 
maldehyd is  now  employed.  The  gas  is  generated  by 
burning  ordinary  sulphur  in  the  room  to  be  disinfected. 


CORROSIVE  SUB  LI  MA  TE.  ^2t7 

All  the  crevices  and  cracks  in  the  room  should  be  closed 
as  carefully  as  possible,  so  as  to  retain  the  gas  in  as  large 
volume  as  possible  within  the  room.  It  should  form 
from  4  to  lo  per  cent,  of  the  volume  of  the  air  of  the 
room,  and  should  be  allowed  to  act  from  twelve  to 
twenty-four  hours.  To  generate  this  amount  of  the  gas, 
it  is  necessary  to  burn  about  ij  kilograms  of  sulphur  for 
each  25-30  cubic  meters  of  space.  This  gas  also  acts 
most  eflEiciently  in  a  moist  state — in  fact,  it  is  of  small 
penetrating  power  in  the  dry  state.  The  moisture  may 
be  generated  by  spraying  the  articles  in  the  room  or  by 
introducing  steam  during  the  time  the  gas  is  being  gen- 
erated. 

The  use  of  sulphur  dioxid  for  purposes  of  disinfection 
is,  at  present,  largely  confined  to  the  disinfection  of 
ships.  ^  The  preference  of  sulphur  dioxid  over  formal- 
dehyd  in  the  disinfection  of  ships  is  due  to  its  efi&ciency 
in  the  destruction  of  rats  and  other  vermin.  In  this  respect 
sulphur  dioxid  is  far  more  efficient  than  formaldehyd. 
In  vessels  infected  with  plague  it  is  especially  desirable 
to  destroy  all  rats  on  board  ship  because  of  their  evident 
capability  of  serving  as  carriers  of  the  infection. 

Hydrocyanic  Acid. — Recently  the  use  of  hydrocyanic 
acid  has  been  advocated  for  the  disinfection  of  rooms. 
Aside  from  its  value  in  the  destruction  of  pathogenic  bac- 
teria, this  gas  possesses  the  additional  value  of  being  par- 
ticularly efficacious  in  the  destruction  of  vermin.  Con- 
trary to  the  generally  accepted  opinion,  this  gas  is  claimed 
to  be  far  less  dangerous  to  those  employing  it  than  was 
formerly  supposed  to  be  the  case. 

Corrosive  Sublimate. — For  a  long  time  corrosive  sub- 
limate had  been  regarded  as  the  most  reliable  and  efficient 
disinfecting  substance,  on  account  of  its  high  germicidal 
powers,  but  it  is  less  highly  esteemed  at  the  present  time, 
because  it  has  been  found  to  have  certain  very  important 
limitations.  It  is  a  most  highly  poisonous  substance,  and 
is  therefore  not  safe  for  general  use.  It  is  also  objection- 
able from  the  fact  that  it  is  precipitated  by  means  of 

^  See  Sect.  162  of  the  Quarantine  Laws  of  the  United  States,  p.  482. 


438  DISINFECTION. 

albuminous  substances,  and  consequently  it  should  not  be 
employed  in  the  presence  of  such  substances.  The  addi- 
tion of  acids  prevents  the  destruction,  to  some  extent,  of 
the  corrosive  sublimate  through  combination  with  albu- 
minous substances.  Tartaric  or  sulphuric  acid  is  best 
adapted  for  this  purpose.  Because  of  its  poisonous  effects, 
it  is  customary  to  add  one  of  the  anilin  dyes  to  give  it  a 
distinctive  color  and  thus  limit  the  danger  of  accidental 
poisoning.  It  is  capable  of  fixing  permanently  any  stains 
on  clothing,  and  is,  in  consequence,  not  adapted  for  use 
with  such  materials.  It  kills  all  bacteria  and  their  spores 
in  a  few  minutes  in  i  :  looo  solution,  and  in  a  few  hours 
in  1 :  5000  solution.  The  mercury  unites  with  the  proto- 
plasm of  the  organisms  and  forms  albuminate  of  mercury, 
and  thus  kills  them. 

Carbolic  Acid. — This  is  a  very  active  germicide,  and  is 
therefore  an  efficient  disinfectant.  It  is  sparingly  soluble 
in  water,  the  extreme  being  about  5  per  cent,  in  saturated 
solution.  A  solution  of  this  strength  kills  bacteria  in  the 
vegetative  stage  in  less  than  a  minute.  Like  corrosive 
sublimate,  carbolic  acid  is  also  rendered  less  effective  by 
the  presence  of  albuminous  substances  in  the  material  to 
be  disinfected.  The  addition  of  sulphuric  acid  increases 
its  action,  and  for  the  roughest  work  a  mixture  of  equal 
parts  of  crude  carbolic  acid  and  commercial  sulphuric 
acid  is  most  serviceable.  This  mixture  is  employed  in  2 
to  3  per  cent,  solution.  Another  mode  of  employment  is 
in  the  form  of  carbol  soap.  This  mixture  is  of  great 
value  in  the  disinfection  of  soiled  clothing  and  bedding, 
inasmuch  as  it  does  not  fix  the  stains,  and  yet  disinfects 
them  efficiently. 

Trikresol. — The  cresols  are  most  efficient  disinfectants, 
and  are  contained  in  considerable  quantities  in  crude 
carbolic  acid.  Trikresol  is  a  mixture  of  the  three  cresols, 
para-,  meta-,  and  ortho-cresol,  in  the  following  propor- 
tions: Para-cresol,  25  per  cent. ;  meta-cresol,  40  per  cent. ; 
ortho-cresol,  35  per  cent.  This  mixture  is  soluble  in  water 
in  the  proportion  of  2  to  5  per  cent.  It  is  poisonous,  and  its 
action  is  also  increased  by  the  addition  of  sulphuric  acid. 


SULPHA  TE  OF  IRON.  439 

Creoliti. — This  substance  has  a  high  disinfectant  value. 
It  is  insoluble  in  water,  but  is  employed  as  an  emulsion 

in  water  in  the  proportion  of  2  to  5  per  cent.      It  is  used 
for  rougher  work,  as  around  kennels,  stables,  and  cellars. 

Nitrate  of  Silver. — The  use  of  this  substance  is'limited 
by  its  cost,  its  poisonous  qualities,  and.  the  facility  with 
which  it  is  precipitated  by  albuminous  substances.  It 
appears,  however,  to  possess  special  value  as  a  disinfec- 
tant of  the  throat  in  convalescent  cases  of  diphtheria. 
The  application  of  a  20  per  cent,  solution  of  nitrate  of 
silver  to  the  throat,  as  recommended  by  Dr.  Hand,  serves 
to  render  it  free  from  diphtheria  bacilli  in  about  seven 
days,  while  the  average  length  of  time  that  they  persist 
in  throats  treated  by  other  methods  is  about  twenty-eight 
days. 

Preparations  of  lyime. — Chlorinated  Lime — This  is 
one  of  the  most  serviceable  disinfectants  known  at  the  pres- 
ent time  on  account  of  its  cheapness  and  because  it  is  not 
so  highly  poisonous  as  many  of  the  other  disinfectants  in 
use.  It  should  contain  at  least  25  per  cent,  of  available 
chlorin  as  hypochlorite.  In  o.  5  to  i  per  cent,  watery  solu- 
tion it  kills  typhoid  and  cholera  organisms  in  ten  min- 
utes. It  is  especially  adapted  for  the  disinfection  of 
typhoid  stools  and  for  use  in  the  disinfection  of  school- 
rooms and  school  furniture.  The  odor  of  chlorinated 
lime  may  be  readily  removed  by  exposing  cloths  satu- 
rated with  a  solution  of  washing  soda  in  the  room  where 
lime  has  been  used. 

Milk  of  Lime,  or  whitewash,  is  also  a  serviceable  disin- 
fectant, and  is  usually  employed  in  the  disinfection  of 
cesspools  and  privy-vaults.  It  is  a  most  efficient  deodo- 
rant, and  in  this  respect  it  serves  a  double  purpose  when 
applied  to  walls  of  cellars,  etc. 

Washing  Soda. — This  is  a  serviceable  disinfectant,  and 
no  doubt  serves  a  good  purpose  when  applied  to  floors  in 
the  ordinary  cleansing  operations.  In  2  per  cent,  solu- 
tion it  is  an  efficient  disinfectant  for  instruments  when 
boiled  in  it  for  ten  minutes. 

Sulphate   of    Iron. — For    rougher    work,    as    privy- 


440  DISINFECTION. 

vaults,  cesspools,  etc.,  this  substance  is  most  frequently 

employed.  It  is  not  a  strong  disinfectant,  but  it  is  ser- 
viceable as  a  deodorant.  It  should  be  used  in  the  pro- 
portion of  I  kilogram  (dissolved  in  lo  liters  of  water)  to 
a  cubic  meter  of  the  contents  of  the  vault. 

Physical  Agents. — The  principal  physical  agents 
employed  for  purposes  of  disinfection  are  dry  and  moist 
heat,  fire,  and  sunlight. 

Dry  Heat — This  agent  is  not  employed  in  ordinary 
disinfection.  Its  use  is  confined  to  the  laboratory,  where 
it  is  employed  in  the  disinfection  of  glassware,  etc. 

Moist  Heat — The  use  of  moist  heat  is  almost  univer- 
sal, and  has  many  advantages  over  chemical  disinfect- 
ants. It  is  entirely  safe  and  very  efficient,  besides  being 
cheap,  so  that  it  has  all  the  requisites.  It  may  be 
employed  in  the  form  of  boiling  water  or  in  the  form  of 
steam.  Boiling  water  added  in  double  quantity  to  typhoid 
or  cholera  stools  disinfects  them  in  an  hour.  It  kills  the 
diphtheria  bacillus  in  five  minutes,  and  the  tubercle 
bacillus  in  ten  minutes,  and  consequently  it  is  most  ser- 
viceable for  the  disinfection  of  napkins  soiled  with  the 
discharges  of  diphtheria  or  tubercular  patients. 

Steam  is  now  used  largely  in  the  disinfection  of 
clothing  and  bedding,  such  as  mattresses  and  pillows, 
which  cannot  be  disinfected  by  means  of  hot  water.  A 
special  apparatus  is  required  for  the  larger  pieces  which 
boards  of  health  are  obliged  to  deal  with.^  In  the  sick- 
room an  ordinary  potato-steamer  or  the  ordinary  milk- 
sterilizing  apparatus  may  be  employed. 

Fire,  of  course,  is  the  best  of  all  disinfectants,  because 
it  is  positive  in  its  action.  It  can,  however,  be  employed 
only  in  the  destruction  of  infected  articles  that  are  of 
little  or  no  further  use.     It  is  frequently  best  to  resort  to 

^  In  these  large  steam  disinfecting  apparatuses  the  air  can  be  exhausted  and 
the  steam  retained  under  pressure.  With  increase  in  pressure  there  is  an  in- 
crease in  temperature,  and  consequently  an  increase  in  the  effectiveness  of  the 
operation.  At  760  mm.  barometric  pressure  water  is  turned  into  steam  at 
100°  C.  (212° F.).  At  a  pressure  of  one  additional  atmosphere  we  obtain  a 
temperature  of  121. 5"  C.  (250°  F.).  At  a  pressure  of  two  additional  atmos- 
pheres we  obtain  a  temperature  of  135°  C.  (275°  F.). 


DISINFECTION  OF  EXCRETA. 


441 


the  use  of  this  efficient  disinfecting  agent,  even  if  the 
infected  articles  are  of  slight  value,  because  we  are  then 
certain  no  danger  can  result  therefrom. 

Sunlight — The  direct  action  of  the  sun's  rays  kills 
non-spore-bearing  organisms  in  half  an  hour.  It  has, 
however,  but  little  penetrating  power,  and  consequently 
it  is  of  limited  applicability.  The  combined  influence 
of  sunlight  and  drying  as  a  purifying  agent  should  not 
be  altogether  ignored,  but  should  not  be  relied  upon 
exclusively. 

Disinfection  of  Infective  Materials. — The  chem- 
ical disinfectants  are  used  principally  by  direct  applica- 
tion to  infected  materials.  Mercuric  chlorid  is  used  in 
solutions  of  I  :  500  to  i  :  4000  strength.  Carbolic  acid  is 
used  in  2  to  5  per  cent,  solutions.  Chlorid  of  lime  is 
employed  in  0.5  to  i  per  cent,  solution,  prepared  from  a 
preparation  having  from  25  to  30  per  cent,  of  available 
chlorin. 

Disinfection  of  Bxcreta. — For  the  disinfection  of 
excreta  solutions  of  carbolic  acid  and  chlorid  of  lime 
are  usually  employed.  The  excreta  should  be  well  mixed 
with  equal  quantities  of  the  disinfectant  solution,  and 
allowed  to  stand  for  several  hours  before  they  are  finally 
disposed  of  Milk  of  lime,  or  caustic  lime,  may  also  be 
used  for  this  purpose.  Mercuric  chlorid  solution  is  not 
adapted  for  the  disinfection  of  excreta,  because  the 
albuminous  material  present  combines  with  the  mercury 
to  form  insoluble  albuminate  of  mercury,  which  is  inert. 
Mercuric  chlorid  is  not  adapted  for  the  disinfection  of 
clothing  and  bedding,  because  it  fixes  any  stains  that 
may  be  present,  and  thus  prevents  their  subsequent  re- 
moval. 

In  order  to  obviate  the  destruction  of  the  disinfectant 
properties  of  mercuric  chlorid  through  the  agency  of 
albuminoid  materials,  acids  may  be  added  to  the  solution. 
In  France  the  following  mixture  is  employed  : 

Mercuric  chlorid 2  grams. 

Tartaric  acid 24       " 

Water      looo       " 


44:2 


DISINFECTION. 


A  few  drops  of  a  5  per  cent,   solution  of  carminate  of 
indigo  are  added  to  give  the  solution  a  distinctive  color. 
In  England  the  following  mixture  is  employed  : 

Mercuric  chlorid I  ounce. 

Hydrochloric  acid lo  ounces. 

Water I  gallon. 

This  solution  is  colored  with  anilin  blue. 

Disinfection  of  the  Sick-room. — The  disinfection 
of  the  sick-room  during  the  time  it  is  occupied  by  the 
patient  is  essential  to  prevent  the  spread  of  infectious 
diseases.  The  prophylactic  measures  necessary  are  de- 
pendent upon  the  nature  of  the  disease,  though,  in  a 
general  way,  they  may  be  summarized  under  three  divi- 
sions: First,  those  applicable  to  the  exanthemata;  second, 
those  applicable  to  diseases  of  the  respiratory  apparatus; 
and  third,  those  applicable  to  diseases  of  the  gastro- 
intestinal tract.  The  principal  diseases  falling  within 
the  first  group  are  small-pox,  measles,  and  scarlet  fever; 
those  of  the  second  group  are  diphtheria,  pneumonia, 
and  tuberculosis;  and  those  of  the  third  group  are  cholera, 
dysentery,  and  typhoid  fever. 

In  the  Exanthemata. — In  the  first  group  of  diseases 
the  infectious  material,  whatever  its  nature,  seems  to  be 
thrown  off  principally  from  the  skin.  It  is  most  essen- 
tial, therefore,  to  prevent  the  emanations  from  the  skin 
gainings  access  to  the  air  of  the  room.  This  is  best 
accomplished  by  daily  anointing  the  patient's  body  with 
some  bland  oil.  The  bed-clothing  is  to  be  removed  with 
as  little  agitation  as  possible,  and  at  once  placed  in  a  tub 
of  water  or  a  weak  antiseptic  solution  before  it  is  removed 
from  the  room.  The  floor,  walls,  furniture,  and  all 
horizontal  surfaces  in  the  room  should  be  wiped  daily 
with  a  damp  cloth.  The  cloth  may  be  dampened  with  a 
2  per  cent,  solution  of  carbolic  acid  to  increase  the 
efficiency  of  the  cleansing  operation.  There  should  be 
abundant  ventilation  of  the  room,  and  the  most  scrupu- 


DISINFECTION  OF  THE  SICK-ROOM.  443 

loiis  cleanliness.  As  soon  as  any  article  of  clothing  or 
bedding  is  soiled,  it  should  be  removed  in  the  manner 
described.  The  sick-room  must  be  rigidly  isolated  from 
the  remainder  of  the  housCj  and  the  family  must  be  ex- 
cluded from  it. 

In  the  Respiratory  Diseases. — In  the  diseases  of  the 
second  group  the  infectious  material  is  contained  in  the 
secretions  of  the  nose  and  throat  and  in  the  expectora- 
tions. The  most  rigid  care  must,  therefore,  be  exercised 
in  the  collection  and  removal  of  this  material.  Great  care 
must  be  taken  to  prevent  the  patient  from  infecting  his 
hands  and  person,  and  thus  everything  with  which  he 
comes  in  contact.  The  sputum  should  be  collected  in  a 
special  receptacle  containing  a  disinfectant  solution  ; 
this  receptacle  must  be  removed  once  or  twice  daily, 
emptied,  and  disinfected.  The  patient's  hands  must  be 
disinfected  frequently  with  a  solution  of  chlorid  of  lime 
or  of  carbolic  acid.  The  nurse  also  should  disinfect  her 
hands  after  each  handling  of  the  patient.  The  clothing 
and  bedding  must  be  removed  as  soon  as  soiled,  in  the 
manner  described  under  the  first  group  of  infectious  dis- 
eases. The  room  must  also  be  disinfected  in  the  manner 
already  described.  The  table  utensils  used  in  feeding 
the  patient  should  be  disinfected  before  they  are  mixed 
with  those  in  use  by  the  family.  All  food  not  eaten  by 
the  patient  should  be  destroyed. 

In  the  Intestinal  Diseases. — In  the  third  group  of  dis- 
eases the  infectious  material  is  contained  in  the  urine 
and  feces  and  in  the  vomit.  All  these  excreta  must  be 
disinfected  by  means  of  equal  quantities  of  chlorid  of 
lime  solution  or  5  per  cent,  carbolic  acid  solution."  Special 
care  is  necessary  in  the  care  of  the  patient's  hands  and 
person.  Daily  disinfection  of  the  body  of  the  patient  is 
necessary  whenever  the  evacuations  are  frequent  and  not 
carefully  collected  and  removed.  All  soiled  clothing  and 
bedding  must  be  removed  and  disinfected.  The  nurse's 
hands  should  be  disinfected  after  handling  the  patient. 


444  DISINFECTION. 

In  the  intestinal  diseases  special  attention  should  be 
given  to  the  purity  of  the  water-supply.  All  the  water 
used  for  drinking-purposes  should  be  boiled  whenever  it 
is  believed  to  be  the  source  of  the  infection.  This  applies 
not  only  to  the  water  used  by  the  patient,  as  is  sometimes 
directed,  but  to  all  the  water  used  by  the  household  or 
community  using  the  water  for  domestic  purposes. 

When  these  prophylactic  measures  are  carefully  fol- 
lowed, the  air  of  the  room  should  be  practically  free  from 
infective  dust.  This  is  the  principal  danger  in  all  the 
infectious  diseases,  aside  from  direct  contact  with  th^ 
patient,  his  clothing,  or  the  excreta.  There  is  no  danger 
of  contracting  any  of  the  infectious  diseases  from  the 
breath  of  the  patient.  None  of  the  specific  pathogenic 
organisms  are  given  off  with  the  expired  air  in  ordinary 
quiet  respiration.  Bacteria  may  be  projected  from  the 
mucous  surfaces  of  the  mouth  and  nose  in  coughing, 
sneezing,  or  energetic  talking,  but  never  in  quiet  respira- 
tion. 

In  Other  Infectious  Diseases — The  prophylactic  meas- 
ures necessary  in  the  other  infectious  diseases  will  be 
apparent  to  anyone  who  is  familiar  with  their  character 
and  the  excreta  with  which  the  infectious  material  leaves 
the  body.  Common  sense  will  teach  any  intelligent 
person  to  apply  the  prophylactic  measures  in  the  right 
direction  if  these  factors  are  borne  in  mind. 

Disinfection  of  Habitations. —  After  recovery  or 
death  from  cholera,  small-pox,  relapsing,  typhoid,  typhus, 
and  scarlet  fevers,  diphtheria,  measles,  cerebrospinal 
meningitis,  and  severe  dysentery,  the  effects  and  rooms 
occupied  by  the  patient  during  sickness  should  be 
promptly  disinfected.  All  large  municipalities  have  a 
specially  trained  force  of  men  who  carry  out  the  details 
of  disinfection  of  habitations  before  the  placard  is  re- 
moved from  the  house. 

The  clothing  and  bedding  which  are  to  be  disinfected 
by  means  of  steam  should  be  carefully  wrapped  in  cloths 


DISINFECTION  OF  THE  PATIENT.  445 

saturated  with  i  per  cent,  carbolic  acid  solution,  placed 
in  a  wagon,  and  taken  to  the  disinfecting  station.  After 
the  bed  has  been  stripped,  all  refuse  matter,  paper,  and 
articles  of  little  value  are  wrapped  in  cloths  saturated 
with  carbolic  acid  and  burned  in  a  stove  or  furnace. 

The  floor,  doors,  windows,  furniture,  and  the  walls 
for  a  distance  oi  \\  meters  from  the  floor  should  be 
washed  with  5  per  cent,  carbolic  acid  solution.  The 
walls  and  ceiling  of  the  room  should  subsequently  be 
sprayed  with  i  :  1000  bichlorid  of  mercury  solution. 
If  the  walls  are  papered,  it  is  advisable  to  remove  care- 
fully the  paper  before  beginning  the  disinfection.  The 
room  is  then  closed  as  tightly  as  possible  and  disinfected 
by  means  of  formaldehyd. 

In  the  disinfection  of  habitations  after  diseases  of  the 
alimentary  type  the  hopper  of  each  water-closet  should 
be  disinfected  by  pouring  into  it  3  liters  of  chlorinated 
lime;  and  the  householder  or  landlord  should  be  instructed 
to  use  in  the  same  manner  i  liter  of  chlorinated  lime 
daily  for  several  days  afterward. 

The  vessels  in  which  the  excretions  of  the  patient 
(stools,  vomit,  sputum)  had  been  collected  should  be 
washed  with  5  per  cent,  carbolic  acid  solution,  and  then 
filled  with  the  same  solution  and  allowed  to  stand  for 
twenty-four  hours  before  they  are  emptied. 

Disinfection  of  the  Patient. — After  convalescence 
has  been  established  the  question  arises,  How  soon  may 
the  patient  mingle  with  the  remainder  of  the  family 
without  danger  of  carrying  the  infection?  It  is  quite 
evident  that  this  period  of  time  will  vary  not  only  with 
different  diseases  but  also  in  the  same  disease.  This  is 
manifest  when  we  take  pains  to  determine  the  length  of 
time  during  which  virulent  diphtheria  bacilli  persist  in 
the  throat  after  all  symptoms  have  subsided.  This  has 
extended  over  a  period  of  three  months  or  more  in  some 
cases,  the  average  being  about  four  weeks. 

In  the  exanthemata  it  is  customary  to  raise  the  quar- 


446  DISINFECTION. 

antine  when  the  physician  reports  the  recovery  of  the 
patient,  but  the  child  is  not  allowed  to  attend  school  for 
thirty  days  afterward.  As  long  as  we  do  not  know  defi- 
nitely the  cause  of  the  exanthemata,  it  is  safest  to  fix  some 
arbitrary  time  during  which  these  patients  must  still  be 
regarded  as  dangerous  to  the  well. 

In  diphtheria  it  is  possible  to  determine  when  the 
patient  is  free  from  the  infectious  agents  by  bacteriologic 
means.  As  soon  as  the  throat,  nose,  and  the  accessory 
cavities  are  free  from  diphtheria  bacilli,  the  patient  may 
safely  mingle  with  the  well.  Unfortunately,  in  the  ex- 
anthemata we  are  unable  to  apply  any  such  practical 
test.  The  only  test  we  possess  is  completion  of  desqua- 
mation. 

In  typhoid  fever  it  has  been  found  that  the  bacilli  per- 
sist in  the  urine  and  feces  for  a  considerable  time,  and 
here  also  it  is  possible  to  apply  the  cultural  test  to  deter- 
mine the  time  when  the  patieut  is  no  longer  a  menace  to 
the  community. 

When  the  patient  has  recovered  from  an  infectious 
disease,  he  should  be  given  a  general  bath  with  soap 
and  water.  In  addition  to  this,  he  may  be  bathed  with 
chlorinated  soda  solution,  and  in  the  exanthemata  it  may 
be  advisable  to  anoint  his  body  again  unless  all  desqua- 
mation has  ceased.  After  a  general  bath  has  been  given, 
the  patient  may  be  allowed  to  mingle  with  the  well.     ' 

In  most  localities  the  convalescent  from  certain  dis- 
eases, especially  small-pox,  is  washed  with  i  :  2000  bi- 
chlorid  of  mercury  solution,  clothed  with  clean  clothing, 
and  then  transferred  to  a  disinfected  room. 

Disinfection  of  Public  Conveyances. — The  danger 
of  disseminating  disease  through  public  conveyances  has 
led  to  a  great  deal  of  discussion,  and  in  many  communi- 
ties it  has  passed  beyond  the  stage  of  discussion.  Many 
local  and  State  boards  of  health  prohibit  the  promiscuous 
expectoration  in  public  places  which  was  once  so  com- 
mon. The  danger  of  disseminating  infectious  diseases 
by  allowing  sick  persons  to  be  conveyed  in  the  ordinary 


DISINFECTION  OF  PUBLIC  CON  I  ^E  YANCES.      447 

public  conveyances  lias  led  to  the  appointment  of  a  com- 
mittee on  car  sanitation  by  the  American  Public  Health 
Association.  This  committee  rendered  and  had  adopted 
the  following  report : 

"  I.  When  a  passenger  is  known  to  be  contagiously- 
ill,  he  should  be  isolated  in  a  compartment  appropriately 
equipped  and  ventilated  in  such  a  manner  as  to  separate 
it  from  the  rest  of  the  car.  Through  trains  should  be 
provided  with  rooms  for  the  sick  as  well  as  state-rooms, 
interchangeable  in  use. 

"2.  The  interior  of  passenger  cars  should  be  plain, 
and  finished  with  hard,  smooth,  and  polished  sur- 
faces. 

"3.  All  furnishings  should  be  as  non-absorbent  as 
possible. 

"4.  Coaches  should  be  furnished  with  effective  means 
for  continuously  supplying  not  less  than  1000  cubic  feet 
of  warm  air  an  hour  for  each  single  seat,  and  for  dis- 
tributing and  removing  the  air  without  troublesome 
draught. 

' '  5.   The  temperature  should  be  regulated. 

"6.  The  cleaning  of  cars  should  be  frequent  and 
thorough. 

"7.  Floors  and  sanitary  lavatory  fixtures  should  be 
frequently  treated  with  a  disinfecting  wash. 

"8.  All  fabrics  in  cars  should  receive  sterilizing  treat- 
ment. All  bed  and  lavatory  linen  should  be  thoroughly 
sterilized  in  the  process  of  laundering. 

' '  9.  Sewage-tanks  and  earth-closets  should  be  provided 
under  the  cars.  The  practice  of  disposing  of  excreta  by 
scattering  it  over  roadbeds  is  dangerous. 

"  10.  Water  and  ice  should  be  obtained  from  the  purest 
available  sources.  The  use  of  tongs  in  handling  ice 
should  be  insisted  upon. 

"11.  The  water- tank  should  be  frequently  cleansed 
and  periodically  sterilized  with  boiling  water  or  other- 
wise. 

"  12.   The  public  should  be  educated  to  use  individual 


448  DISINFECTION. 

cups.  Paper  paraffined  cups  might  be  provided  by  a 
cent-in-the-slot  device. 

"13.  The  use  of  canned  goods  in  buffet-car  service 
makes  careful  inspection  of  such  goods  imperative.  Fruits 
and  all  eatables  before  and  after  purchase  should  be  stored 
with  care,  to  avoid  all  unnecessary  exposure  to  street 
and  car  dust. 

"  14.  The  filthy  habit  of  spitting  on  car  floors  should 
be  dealt  with  in  a  manner  to  cause  its  prompt  discontinu- 
ance. It  should  be  punished  as  one  of  the  most  flagrant 
of  the  thoughtless  offences  against  the  public  right  to 
health. 

"  15.  Station  premises  should  receive  attention  directed 
to  general  cleanliness  of  floors,  furnishings,  air,  sanita- 
ries,  lavatories,  platforms,  and  approaches,  and  should  be 
plentifully  supplied  with  approved  disinfecting  material." 

The  Disinfection  of  I/ibraries. — Formaldehyd  gas 
may  be  conveniently  applied  for  the  disinfection  of 
books  by  the  use  of  a  Schering  lamp.  A  perfectly  tight 
box  should  be  provided.  It  should  be  lined  inside  with 
a  heavy  calendered  paper,  and  the  joints  tightly  closed. 
The  books  should  be  opened  out  with  all  leaves  exposed, 
and  placed  on  shelves  or  racks  within  the  box. 

More  convenient  than  a  box  would  be  a  small  closet 
with  a  lattice- work  or  shelves  upon  which  to  expose  the 
books. 

The  problem  of  disinfecting  a  number  of  books  at 
once  is  quite  a  difficult  one.  Library  books  are  infected 
through  handling.  The  infection  is  apt  to  adhere  to 
the  leaves  of  the  book,  and  each  individual  leaf  must 
be  opened  in  such  a  way  as  to  become  penetrated  by  the 
formaldehyd  gas.  Large  libraries  are  now  generally 
equipped  with  disinfecting  apparatus  so  as  to  be  in  a 
position  to  disinfect  books  that  may  have  been  in  rela- 
tion with  any  of  the  infectious  diseases. 

Barber-shops. — The  danger  of  contracting  disease  in 
barber-shops  is  now  receiving  more  general  recognition. 
The  selection  of  a  barber  is  evidently  a  matter  of  some 


BARBER-SHOPS.  449 

consideration,  and  should  be  influenced  largely  by  the 
care  which  he  exercises  to  prevent  the  dissemination  of 
contagion.  Health  Commissioner  Lederie  recently  issued 
the  following  ten  rules  for  the  governance  of  barbers  in 
Greater  New  York : 

1.  Barbers  must  wash  their  hands  thoroughly  with 
soap  and  hot  water  before  attending  any  person. 

2.  No  alum  or  other  astringent  shall  be  used  in  stick 
form.  If  used  at  all  to  stop  flow  of  blood,  it  must  be 
applied  in  powder  form. 

3.  The  use  of  powder-puffs  is  prohibited. 

4.  No  towel  shall  be  used  for  more  than  one  person 
without  being  washed. 

5.  The  use  of  sponges  is  prohibited. 

6.  Mugs  and  shaving-brushes  shall  be  thoroughly 
washed  after  use  on  each  person. 

7.  Combs,  razors,  clippers,  and  scissors  shall  be  thor- 
oughly cleansed  by  dipping  in  boiling  water  or  other 
germicide  after  separate  use  thereof 

8.  No  barber,  unless  he  be  a  licensed  physician,  shall 
prescribe  for  any  skin  disease. 

9.  Floors  must  be  swept  or  mopped  every  day  and  all 
furniture  and  woodwork  kept  free  from  dust. 

10.  Hot  and  cold  water  must  be  provided. 

Similar  rules  have  been  adopted  by  the  Board  of 
Health  of  New  Orleans  and  of  other  cities. 

29 


CHAPTER    XIX. 
QUARANTINE. 

Quarantine  applies  to  the  detention  of  ships  with 
cases  of  infectious  diseases  on  board  to  the  ports  in  which 
they  are  found,  to  the  detention  of  persons  in  infected 
localities,  and  to  the  detention  of  the  occupants  of  a 
house  in  which  there  is  a  case  of  infectious  disease.  The 
first  is  commonly  spoken  of  as  maritime  quarantine,  the 
detention  of  persons  in  infected  localities  as  inland 
quarantine,  and  the  last  as  house  quarantine. 

Maritime  Quarantine. — Maritime  quarantine  consists 
of  the  detention  of  the  infected  ship,  the  isolation  of  the 
sick  in  a  special  hospital  at  the  quarantine  station,  the 
disinfection  of  the  ship  and  its  cargo  as  well  as  the  cloth- 
ing and  bedding  of  the  well,  the  detention  of  all  well 
persons  in  barracks  until  after  the  period  of  incubation 
of  the  particular  disease  has  elapsed  and  all  danger  of 
dissemination  has  been  eliminated.  The  period  of  deten- 
tion, the  mode  of  disinfection,  as  well  as  all  the  other 
prophylactic  measures  employed,  will  depend  entirely 
upon  the  character  of  the  disease,  its  period  of  incuba- 
tion, and  the  nature  of  the  ship's  cargo.  The  disin- 
fecting agents  commonly  employed  are  superheated 
steam  and  formaldehyd. 

The  following  States  still  maintain  quarantine  stations  : 
Massachusetts,  New  York,  Pennsylvania,  Maryland,  and 
Texas.  In  all  the  other  States  having  sea,  lake,  or  gulf 
ports  the  quarantine  regulations  are  in  charge  of  the 
Public  Health  Service  of  the  United  States. 

The  United  States  maintains  quarantine  stations  at  the 
following  points :  East  Port  and  Portland,   Me. ;    Provi- 

450 


INLAND  QUARANTINE.  451 

deuce,  R.  I. ;  Perth  Amboy,  N.  J. ;  Reedy  Island  and 
Delaware  Breakwater,  Del. ;  Alexandria  and  Cape  Charles, 
Va. ;  Washington,  Newbern,  and  Cape  Fear,  N.  C. ; 
Charleston,  Georgetown,  Beaufort,  and  Port  Royal,  S.  C. ; 
Savannah  and  Brnnswick,  Ga, ;  Cumberland  Sound,  St. 
John's  River,  Biscay ne  Bay,  Key  West,  Punta  Rossa, 
Bocogrande,  Tampa  Bay,  St.  Andrew,  St.  Joseph,  Port 
Inglis,  Cedar  Keys,  St.  George's  Sound,  and  Pensacola, 
Fla. ;  Fort  Morgan,  Ala. ;  Gulf  and  Pascogoula,  Miss. ; 
New  Orleans,  La. ;  Laredo,  Eagle  Pass,  and  El  Paso, 
Tex. ;  San  Diego,  San  Pedro,  Redondo,  Santa  Barbara, 
Port  Harford,  Monterey,  San  Francisco,  Fort  Bragg,  and 
Eureka,  Cal. ;  Columbia  River,  Florence,  Newport,  Coos 
Bay,  Ore. ;  Port  Townsend  and  Port  Angles,  Wash. 

Inland  Quarantine. — Inland  quarantine  is  employed 
in  times  of  epidemics  confined  to  certain  localities  of  the 
country.  In  the  United  States  this  form  of  quarantine 
has  been  frequently  applied  to  localities  infected  with 
yellow  fever.  The  prevention  of  all  communication  with 
the  locality  is  sometimes  enforced  by  means  of  a  line  of 
guards  surrounding  the  locality,  and  hence  is  frequently 
spoken  of  as  "shotgun"  quarantine.  Where  important 
railroad  centers  are  involved  in  an  infected  area,  this 
form  of  quarantine  is  commonly  known  as  railroad  quar- 
antine, and  all  intercourse  with  the  infected  area  by  rail 
is  stopped.  All  merchandise  and  mail  coming  from  the 
infected  area  are  disinfected  whenever  traffic  is  not  com- 
pletely at  a  standstill. 

The  extension  of  inland  quarantine  to  interstate  com- 
merce and  traffic  is  known  as  interstate  quarantine,  and 
becomes  necessary  where  large  areas  are  infected  and 
there  is  danger  of  general  dissemination  of  the  infectious 
disease.  The  establishment  of  definite  interstate  quar- 
antine regulations  by  the  U.  S.  Treasury  department 
obviates  in  large  part  the  confusion  which  frequently 
existed  during  an  epidemic  of  yellow  fever,  because  of 
the  conflicting,  and  in  many  instances  ridiculous,  quar- 


452  Q  UARANTINE. 

antine  regulations  formulated  by  State,  county,  and 
municipal  authorities. 

Isolation  or  House  Quarantine. —  The  infectious 
diseases  against  which  house  quarantine  is  usually  em- 
ployed are  small-pox,  scarlet  fever,  diphtheria,  cerebro- 
spinal meningitis,  cholera,  typhus  and  typhoid  fevers, 
yellow  fever,  relapsing  fever,  and  leprosy.  Plague  is  now 
also  included  in  this  category. 

The  patient  suffering  from  any  of  these  infectious  dis- 
eases should  be  isolated  from  the  rest  of  the  family,  pref- 
erably in  a  room  on  an  upper  floor  of  the  house.  All 
persons  residing  in  the  house  are  prohibited  from  attend- 
ing any  school  whatsoever,  as  well  as  from  going  to  any 
other  places  of  public  assembly.  No  one  is  allowed  to 
enter  the  house  during  the  course  of  the  disease  except 
those  in  direct  charge  of  the  patient,  and  no  one  is  per- 
mitted to  visit  the  sick-room  except  the  physicians  and 
attendants.  The  house  is  placarded  by  the  local  health 
authorities  with  a  placard  indicating  the  nature  of  the 
disease  and  the  danger  of  communicating  the  disease  to 
others.  The  placard  is  not  removed  by  the  health 
authorities  until  after  the  patient  has  either  recovered 
or  died,  and  the  premises  have  been  thoroughly  disin- 
fected. 

Value  of  Disinfection  and  Isolation. — It  is  impos- 
sible to  give  definite  information  with  regard  to  the  value 
of  disinfection  alone,  because  at  the  present  time  it  is 
almost  always  practised  along  with  isolation.  The  value 
of  these  measures  in  such  a  disease  as  small-pox  is  well 
known.  In  other  diseases  they  are  no  doubt  of  equal 
value.  The  only  figures  obtainable  which  bear  directly 
upon  this  point  are  contained  in  the  reports  of  the  State 
Board  of  Health  of  Michigan.  In  the  report  for  the 
year  1898  are  given  some  comparative  observations  made 
during  a  number  of  outbreaks  of  diphtheria  and  scarlet 
fever  in  that  State  during  the  eleven  years  from  1887  to 
and  including  1898.  In  some  of  these  outbreaks  isola- 
tion and  disinfection  were  enforced,  in  others  they  were 


VAL  UE  OF  DISINFECTION  AND  ISOLA  TION.    45  3 


Average     cases 
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VAL  UE  OF  DISINFECTION  AND  ISOLA  TION.    45  5 

neglected.  The  detailed  results  are  given  in  Tables  I, 
and  11. ,  and  are  also  graphically  presented  in  Chart  I. 

These  studies  indicate  that  34,784  cases  and  7103 
deaths  were  saved  from  diphtheria,  and  31,228  cases  and 
1012  deaths  from  scarlet  fever,  during  the  eleven  years. 
If  we  take  into  consideration  the  immense  financial  sav- 
ing alone  that  is  represented  by  these  figures,  we  see  the 
great  economic  value  to  the  State  of  the  application  of 
these  preventive  measures,  a  large  part  of  which  can  no 
doubt  be  safely  attributed  to  the  employment  of  disin- 
fectants. 

The  value  of  isolation  and  disinfection  as  usually 
practised  is  shown  graphically  in  the  following  chart, 
reproduced  from  the  proceedings  of  the  third  annual 
conference  of  the  health  officers  of  Michigan,  1896: 


Isolation  and  Disinfection  in  Scarlet  Fever  and  Diph- 
theria ill  Michigan  during  the  Five   Years  1886-go. 


Scarlet  Fever. 

Isolation  and  disinfection 
neglected     in    366  1  enforced,     in     361 
outbreaks,  av'ge —    outbreaks,  av'ge — 

Cases.    I   Deaths.  |    Cases.    |  Deaths. 


t 


Diphtheria. 
Isolation  and  disinfection 


neglected  in  317 
outbreaks,  av'ge— 
Cases.    I  Deaths. 


enforced  in  252 
outbreaks,  av'ge — 
Cases.     I  Deaths. 


Figure  63  represents  influence  of  isolation  and  disin- 
fection in  scarlet  fever  according  to  recent  experience  in 
England.  ^ 

^  Jour,  of  Hygiene,  vol.  i.,  igoi. 


456  QUARANTINE. 

Period  of  Isolation. — The  period  of  time  during 
which  the  infectiveness  of  a  patient  continues  varies  with 
each  disease.  In  the  exanthemata  the  quarantine  is 
usually  raised  two  weeks  after  the  eruption  has  entirely 
disappeared,  except  for  small-pox,  for  which  the  period 
of  isolation  is  thirty  days.     In  diphtheria  the  quarantine 


-  No.  of  cases  without  isolation 
and  disin/ectiott. 

i^    I 

No.  of  cases  under  imperfect 
'  ~     isolation  and  disinfection. 
No.  of  cases  when  isolation 
and  disinfection  are  aj>- 
proxiinately  perfect. 
Inter-epiiUme  penad.  _ 

^pieteiTue  period. 

Fig.  63. — Isolation  and  disinfection  in  scarlet  fever. 

is  not  raised  until  cultures  taken  from  the  throat  of  the 
patient  fail  to  show  the  presence  of  the  diphtheria  bacil- 
lus. This  period  varies  very  greatly  in  different  cases, 
ranging  from  five  to  one  hundred  or  more  days  after  the 
total  disappearance  of  the  membrane. 

Period  of  Detention  of  Those  Exposed  to  the 
Infectious  Diseases. — Those  exposed  to  the  infectious 
diseases  are  detained  until  after  the  period  of  incubation 
of  the  particular  disease  has  elapsed.  The  following 
table  shows  the  period  of  incubation  of  the  more  com- 
mon infectious  diseases: 

Small-pox 12  days. 

Measles 10  " 

Scarlet  fever . 3  " 

Diphtheria 3  " 

Cholera 10  " 

Typhoid  fever 14  " 

■  Yellow  fever 5  " 

If  no  new  outbreaks  occur  during  the  period  of  de- 
tention among  those  who  have  been  exposed  to  the  infec- 
tion, the  quarantine  is  raised  after  the  period  of  incuba- 
tion of  the  particular  disease  has  elapsed. 


MARITIME  QUARANTINE.  457 

Maritime  Quarantine.— Maritime  quarantine  is  prac- 
tised against  cliolera,  t\-plius  fever,  yellow  fever,  small- 
pox, leprosy,  and  plague,  though  any  of  the  acute  infec- 
tious diseases  may  be  quarantined. 

In  a  recent  paper  on  modern  quarantine  in  Canada  and 
the  United  States,  Dr.  Montizambert,  of  Quebec,  states 
that  the  requirements  for  a  quarantine  station  are  held  to 
be  as  follows: 

"  I,  A  boarding  station,  so  placed  as  to  command  the 
channel  leading  to  the  port. 

"2.  A  boarding  steamer  fitted  with  hospital  cabins,  for 
landing  the  sick,  and  with  appliances  for  disinfecting  in 
the  offing  ships'  hospitals  with  mercuric  chlorid  douche, 
and  with  steam  when  such  disinfection  is  found  to  b?  all 
that  the  vessel  requires. 

"3.  iV  reserve  steamer  to  replace  the  usual  boarding 
steamer  on  emergency,  and — where  the  station  is  isolated 
— to  act  as  a  supply  and  mail  steamer,  for  forwarding 
convalescents,  etc. 

"4.  An  anchorage  for  vessels  under  quarantine  or  ob- 
servation. It  should  be  placed  conveniently  for  the  main 
establishment,  and  safely  remote  from  the  track  of  com- 
merce. 

"5.  A  deep-water  pier.  The  depth  of  water  at  low 
tide  at  its  end  should  be  at  least  equal  to  the  draught  of 
the  largest  vessels  coming  to  the  port,  with  a  frontage 
sufficient  for  such  vessels  to  moor  to  it  if  required.  Upon 
this  pier  there  should  be  constructed — 

"  «.  A  warehouse; 

''3.   Elevated  tanks  for  disinfecting  solutions; 

"  ^.  A  disinfecting-house  containing  steam  disinfecting 
cylinders; 

"  rt'.  Sulphur  furnace,  engine,  exhaust  fans,  etc.,  for 
fumigation. 

"6.  A  lazarette  or  hospital  for  the  treatment  of  infec- 
tious diseases. 

"7.  Separate  accommodations  for  non-infectious  cases 
from  infected  vessels  in  quarantine. 


458  QUARANTINE. 

" '  8.  Detention-houses  for  the  detention,  under  observa- 
tion, in  groups,  of  "  suspects  "  or  persons  who  have  been 
exposed  to  infection. 

"  9.   Quarters  for  officers  and  staff. 

' '  10.  Telegraphic  communication  with  the  rest  of  the 
world.  Telephonic  communication  between  the  different 
parts  of  the  station. 

"11.   A  bacteriologic  laboratory. 

"12.  A  cremation  furnace  for  the  disposal  of  the  bodies 
of  those  who  have  died  of  infectious  diseases. ' ' 

Within  the  last  few  years  most  of  the  quarantine  sta- 
tions have  been  equipped  with  formaldehyd  gas  generators 
for  use  in  the  disinfection  of  infected  vessels. 

All  maritime  and  interstate  quarantine  powers  of  the 
United  States  have  been  conferred  upon  the  Supervising 
Surgeon-General  of  the  Public  Health  and  Marine-Hos- 
pital Service,  and  this  service  is  under  the  direction  of 
the  Secretary  of  the  Treasury,  The  following  is  a  trans- 
cript of  the  acts  of  Congress  conferring  these  powers,  as 
well  as  the  quarantine  laws  of  the  United  States  : 

QUARANTINE    LAWS   OF   THE   UNITED   STATES. 

AN  ACT  TO  Increase  the  Efficiency  and  Change  the  Name  of  the 
United  States  Marine-Hospital  Service. 

[Approved  July  i,  1902.] 

Be  it  enacted  by  the  Senate  atid  House  of  Represefitatives  of  the 
United  States  of  America  in  Congress  assembled,  That  the  United 
States  Marine-Hospital  Service  shall  hereafter  be  known  and  des- 
ignated as  the  Public  Health  and  Marine-Hospital  Service  of  the 
United  States,  and  the  Supervising  Surgeon-General  and  the 
officers  now  or  hereafter  commissioned  under  the  Act  of  January 
fourth,  eighteen  hundred  and  eighty-nine,  entitled  "An  Act  to 
regulate  appointments  in  the  Marine-Hospital  Service  of  the 
United  States,"  and  Acts  amendatory  thereof,  shall  hereafter  be 
known  as  the  Surgeon-General,  surgeons,  passed  assistant  sur- 
geons, and  assistant  surgeons  of  the  Public  Health  and  Marine- 
Hospital  Service  of  the  United  States.  Nothing  in  this  Act  con- 
tained shall  be  held  or  construed  to  discharge  any  of  the  officers 
above  named,  or  any  of  the  acting  assistant  surgeons,  pharmacists, 
and  other  employees  of  the  Marine-Hospital  Service,  or  to  deprive 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  459 

any  ofificer  of  his  commission  or  the  benefits  derived  by  longevity 
of  service.  The  care  of  sick  and  disabled  seamen  and  all  other 
duties  now  required  by  law  to  be  performed  by  the  Marine-Hos- 
pital Service  shall  hereafter  be  performed  by  the  Public  Health 
and  Marine-Hospital  Service,  and  all  funds  and  appropriations 
now  provided  by  law  for  use  by  the  Marine-Hospital  Service  and 
all  properties  and  rights  pertaining  to  said  service  shall  be  avail- 
able for  use  for  like  purposes  and  in  like  manner,  under  the 
Treasury  Department,  by  the  Public  Health  and  Marine- Hospital 
Service. 

Sec.  2.  That  the  salary  of  the  Surgeon-General  of  the  Public 
Health  and  Marine-Hospital  Service  shall  be  five  thousand  dol- 
lars per  annum,  and  the  salaries  and  allowances  of  the  commis- 
sioned medical  officers  of  said  service  shall  be  the  same  as  now 
provided  by  regulations  of  the  Marine-Hospital  Service. 

Sec.  3.  That  commissioned  medical  officers,  when  detailed  by 
the  Surgeon-General  for  duty  in  the  Public  Health  and  Marine- 
Hospital  Bureau  at  Washington,  District  of  Columbia,  in  charge 
of  the  administrative  divisions  thereof,  namely,  marine  hospitals 
and  relief,  domestic  quarantine,  foreign  and  insular  quarantine, 
personnel  and  accounts,  sanitary  reports  and  statistics,  and  scien- 
tific research,  shall,  while  thus  serving,  be  assistant  surgeons-gen- 
eral of  the  Public  Health  and  Marine-Hospital  Servdce,  but  their 
pay  and  allowances  shall  be  the  same  as  now  provided  by  regu- 
lations of  the  Marine- Hospital  Service  for  officers  in  charge  of 
said  divisions  ;  and  the  senior  officer  thus  sendng  shall  be  the 
assistant  within  the  meaning  of  section  one  hundred  and  seventy- 
eight,  Revised  Statutes  of  the  United  States :  Provided,  however, 
That  no  such  officer  shall  be  detailed  in  charge  of  said  divisions 
who  is  below  the  rank  of  passed  assistant  surgeon. 

Sec.  4.  That  the  President  is  authorized,  in  his  discretion,  to 
utilize  the  Public  Health  and  Marine-Hospital  Service  in  times 
of  threatened  or  actual  war  to  such  extent  and  in  such  manner 
as  shall  in  his  judgment  promote  the  public  interest  without,  how- 
ever, in  any  wise  impairing  the  efficiency  of  the  service  for  the 
purposes  for  which  the  same  was  created  and  is  maintained. 

Sec.  5.  That  there  shall  be  an  advisory  board  for  the  hygienic 
laborator}^  provided  by  the  Act  of  Congress  approved  March 
third,  nineteen  hundred  and  one,  for  consultation  with  the  Sur- 
geon-General of  the  Public  Health  and  Marine-Hospital  Service 
relative  to  the  investigations  to  be  inaugurated,  and  the  methods 
of  conducting  the  same,  in  said  laboratory.  Said  board  shall 
consist  of  three  competent  experts,  to  be  detailed  from  the  x\rmy, 
the  Navy,  and  the  Bureau  of  Animal  Industry  by  the  Surgeon- 
General  of  the  Army,  the  Surgeon-General  of  the  Navy,  and  the 
Secretary  of  Agriculture,  respectively,  which  experts,  with  the 
director  of  the  said  laboratory,  shall  be  ex  officio  members  of  the 
board,  and  serve  without  additional  compensation.  Five  other 
members  of  said  board  shall  be  appointed  by  the  Surgeon-Gen- 


460  QUARANTINE. 

eral  of  Public  Health  and  Marine-Hospital  Service,  with  the  ap- 
proval of  the  Secretary  of  the  Treasury,  who  shall  be  skilled  in 
laboratory  work  in  its  relation  to  the  public  health,  and  not  in 
the  regular  employment  of  the  Government.  The  said  five  mem- 
bers shall  each  receive  compensation  of  ten  dollars  per  diem  while 
serving  in  conference,  as  aforesaid,  together  with  allowance  for 
actual  and  necessary  traveling  expenses  and  hotel  expenses  while 
in  conference.  Said  conference  is  not  to  exceed  ten  days  in  any 
one  fiscal  year.  The  term  of  service  of  the  five  members  of  said 
board,  not  in  the  regular  employment  of  the  Government,  first 
appointed  shall  be  so  arranged  that  one  of  said  members  shall 
retire  each  year,  the  subsequent  appointments  to  be  for  a  period 
of  five  years.  Appointments  to  fill  vacancies  occurring  in  a 
manner  other  than  as  above  provided  shall  be  made  for  the  un- 
expired term  of  the  member  whose  place  has  become  vacant. 

Sec.  6.  That  there  shall  be  appointed  by  the  Surgeon-General, 
with  the  approval  of  the  Secretary  of  the  Treasury,  whenever,  in 
the  opinion  of  the  Surgeon-General,  commissioned  medical  officers 
of  the  Public  Health  and  Marine-Hospital  Service  are  not  avail- 
able for  this  duty  by  detail,  competent  persons  to  take  charge  of 
the  divisions,  respectively,  of  chemistry,  zoology,  and  pharma- 
cology of  the  hygienic  laboratory,  who  shall  each  receive  such 
pay  as  shall  be  fixed  by  the  Surgeon-General,  with  the  approval 
of  the  Secretary  of  the  Treasury.  The  director  of  the  said  labora- 
tory shall  be  an  officer  -detailed  from  the  corps  of  commissioned 
medical  officers  of  the  Public  Health  and  Marine-Hospital  Ser- 
vice, as  now  provided  by  regulations  for  said  detail  from  the 
Marine-Hospital  Service,  and  while  thus  serving  shall  have  the 
pay  and  emoluments  of  a  surgeon  :  Provided,  That  all  commis- 
sioned officers  of  the  Public  Health  and  Marine-Hospital  Service 
not  below  the  grade  of  passed  assistant  surgeon  shall  be  eligible 
to  assignment  to  duty  in  charge  of  the  said  divisions  of  the 
hygienic  laboratory,  and  while  serving  in  such  capacity  shall  be 
entitled  to  the  pay  and  emoluments  of  their  rank. 

Sec.  7.  That  when,  in  the  opinion  of  the  Surgeon-General  of 
the  Public  Health  and  Marine-Hospital  Service  of  the  United 
States,  the  interests  of  the  public  health  would  be  promoted  by  a 
conference  of  said  service  with  State  or  Territorial  boards  of 
health,  quarantine  authorities,  or  State  health  officers,  the  Dis- 
trict of  Columbia  included,  he  may  invite  as  many  of  said  health 
and  quarantine  authorities  as  he  deems  necessary  or  proper  to 
send  delegates,  not  more  than  one  from  each  State  or  Territory 
and  District  of  Columbia,  to  said  conference :  Provided,  That  an 
annual  conference  of  the  health  authorities  of  all  the  States  and' 
Territories  and  the  District  of  Columbia  shall  be  called,  each  of 
said  States,  Territories,  and  the  District  of  Columbia  to  be  enti- 
tled to  one  delegate  :  And  provided,  further,  That  it  shall  be  the 
duty  of  the  said  Surgeon-General  to  call  a  conference  upon  the 
application  of  not  less  than  five  State  or  Territorial  boards  of 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  461 

health,  quarantine  authorities,  or  State  health  oihcers,  each  of 
said  States  and  Territories  joining  in  such  request  to  be  repre- 
sented by  one  delegate. 

Sec.  8.  That  to  secure  uniformity  in  the  registration  of  mortal- 
ity, morbidity,  and  vital  statistics  it  shall  be  the  duty  of  the  Sur- 
geon-General of  the  Public  Health  and  Marine-Hospital  Service, 
after  the  annual  conference  required  by  section  seven  to  be  called, 
to  prepare  and  distribute  suitable  and  necessary  forms  for  the  col- 
lection and  compilation  of  such  statistics,  and  said  statistics,  when 
transmitted  to  the  Public  Health  and  Marine-Hospital  Bureau 
on  said  forms,  shall  be  compiled  and  published  by  the  Public 
Health  and  Marine-Hospital  Service  as  a  part  of  the  health  reports 
published  by  said  service. 

Sec.  9.  That  the  President  shall  from  time  to  time  prescribe 
rules  for  the  conduct  of  the  Public  Health  and  Marine- Hospital 
Service.  He  shall  also  prescribe  regulations  respecting  its  inter- 
nal administration  and  discipline,  and  the  uniforms  of  its  officers 
and  employees.  It  shall  be  the  duty  of  the  Surgeon-General  to 
transmit  annually  to  the  Secretary  of  the  Treasury,  for  trans- 
mission by  said  Secretary  to  Congress,  a  full  and  complete  report 
of  the  transactions  of  said  service,  including  a  detailed  statement 
of  receipts  and  disbursements. 

AN  ACT  Granting  Additional  Quarantine  Powers  and  Imposing  Ad- 
ditional Duties  upon  the  Marine-Hospital  Service. 

[Approved,  February  15,  1893.] 

^e  it  enacted  by  the  Senate  a?id  House  of  Repi-esentatives  of  the 
United  States  of  America  in  Congress  assembled,  That  it  shall  be 
unlawful  for  any  merchant  ship  or  other  vessel  from  any  foreign 
port  or  place  of  [to]  enter  any  port  of  the  United  States  except 
in  accordance  with  the  provisions  of  this  act  and  with  such  rules 
and  regulations  of  State  and  municipal  health  authorities  as  may 
be  made  in  pursuance  of,  or  consistent  with,  this  act ;  and  any 
such  vessel  which  shall  enter,  or  attempt  to  enter,  a  port  of  the 
United  States  in  violation  thereof  shall  forfeit  to  the  United 
States  a  sum,  to  be  awarded  in  the  discretion  of  the  court,  not 
exceeding  five  thousand  dollars,  which  shall  be  a  lien  upon  said 
vessel,  to  be  recovered  by  proceedings  in  the  proper  district  court 
of  the  United  States.  In  all  such  proceedings  the  United  States 
district  attorney  for  such  district  shall  appear  on  behalf  of  the 
United  States ;  and  all  such  proceedings  shall  be  conducted  in 
accordance  with  the  rules  and  laws  governing  cases  of  seizure  of 
vessels  for  violation  of  the  revenue  laws  of  the  United  States. 

Sec.  2.  That  any  vessel  at  any  foreign  port  clearing  for  any 
port  or  place  in  the  United  States  shall  be  required  to  obtain 
from  the  consul,  vice-consul,  or  other  consular  officer  of  the 
United  States  at  the  port  of  departure,  or  from  the  medical  officer 
where  such   officer  has  been  detailed  by  the   President  for  that 


462  QUARANTINE. 

purpose,  a  bill  of  health,  in  duplicate,  in  the  form  prescribed  by 
the  Secretary  of  the  Treasury,  setting  forth  the  sanitary  history 
and  condition  of  said  vessel,  and  that  it  has  in  all  respects  com- 
plied with  the  rules  and  regulations  in  such  cases  prescribed  for 
securing  the  best  sanitary  condition  of  the  said  vessel,  its  cargo, 
passengers,  and  crew ;  and  said  consular  or  medical  officer  is. 
required,  before  granting  such  duplicate  bill  of  health,  to  be 
satisfied  that  the  matters  and  things  therein  stated  are  true  ;  and 
for  his  services  in  that  behalf  he  shall  be  entitled  to  demand  and 
receive  such  fees  as  shall  by  lawful  regulation  be  allowed,  to  be 
accounted  for  as  is  required  in  other  cases. 

The  President,  in  his  discretion,  is  authorized  to  detail  any 
medical  officer  of  the  Government  to  serve  in  the  office  of  the 
consul  at  any  foreign  port  for  the  purpose  of  furnishing  informa- 
tion and  making  the  inspection  and  giving  the  bills  of  health 
hereinbefore  mentioned.  Any  vessel  clearing  and  sailing  from 
any  such  port  without  such  bill  of  health,  and  entering  any  port 
of  the  United  States,  shall  forfeit  to  the  United  States  not  more 
than  five  thousand  dollars,  the  amount  to  be  determined  by  the 
court,  which  shall  be  a  lien  on  the  same,  to  be  recovered  by  pro- 
ceedings in  the  proper  district  court  of  the  United  States.  In  all 
such  proceedings  the  United  States  district  attorney  for  such 
district  shall  appear  on  behalf  of  the  United  States  ;  and  all  such 
proceedings  shall  be  conducted  in  accordance  Avith  the  rules  and 
laws  governing  cases  of  seizure  of  vessels  for  violation  of  the 
revenue  laws  of  the  United  States. 

Sec.  3.  That  the  Supervising  Surgeon-General  of  the  Marine- 
Hospital  Service  shall,  immediately  after  this  act  takes  effect, 
examine  the  quarantine  regulations  of  all  State  and  municipal 
boards  of  health,  and  shall,  under  the  direction  of  the  Secretary 
of  the  Treasury,  cooperate  with  and  aid  State  and  municipal 
boards  of  health  in  the  execution  and  enforcement  of  the  rules 
and  regulations  of  such  boards  and  in  the  execution  and  en- 
forcement of  the  rules  and  regulations  made  by  the  Secretary  of 
the  Treasury,  to  prevent  the  introduction  of  contagious  or  in- 
fectious diseases  into  the  United  States  from  foreign  countries, 
and  into  one  State  or  Territory  or  the  District  of  Columbia 
from  another  State  or  Territory  or  the  District  of  Columbia; 
and  all  rules  and  regulations  made  by  the  Secretary  of  the 
Treasury  shall  operate  uniformly  and  in  no  manner  discriminate 
against  any  port  or  place  ;  and  at  such  ports  and  places  within 
the  United  States  as  have  no  quarantine  regulations  under  State 
or  municipal  authority,  where  such  regulations  are,  in  the  opinion 
of  the  Secretary  of  the  Treasury,  necessary  to  prevent  the  intro- 
duction of  contagious  or  infectious  diseases  into  the  United 
States  from  foreign  countries,  or  into  one  State  or  Territory  or 
the  District  of  Columbia  from  another  State  or  Territory  or  the 
District  of  Columbia,  and  at  such  ports  and  places  within  the 
United    States    where    quarantine    regulations    exist    under    the 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  463 

authority  of  the  State  or  municipality  which,  in  the  opinion  of 
the  Secretary  of  the  Treasury,  are  not  sufficient  to  prevent  the 
introduction  of  such  diseases  into  the  United  States,  or  into 
one  State  or  Territory  or  the  District  of  Columbia  from  another 
State  or  Territory  or  the  District  of  Columbia,  the  Secretary  of 
the  Treasury  shall,  if  in  his  judgment  it  is  necessary  and  proper, 
make  such  additional  rules  and  regulations  as  are  necessary  to 
prevent  the  introduction  of  such  diseases  into  the  United  States 
from  foreign  countries,  or  into  one  State  or  Territory  or  the 
District  of  Columbia  from  another  State  or  Territory  or  the  Dis- 
trict of  Columbia,  and  when  said  rules  and  regulations  have  been 
made  they  shall  be  promulgated  by  the  Secretary  of  the  Treasury 
and  enforced  bv  the  sanitary  authorities  of  the  States  and  munici- 
palities, where  the  State  or  municipal  health  authorities  will  under- 
take to  execute  and  enforce  them  ;  but  if  the  State  or  municipal 
authorities  shall  fail  or  refuse  to  enforce  said  rules  and  regulations, 
the  President  shall  execute  and  enforce  the  same  and  adopt  such 
measures  as  in  his  judgment  shall  be  necessary  to  prevent  the 
introduction  or  spread  of  such  diseases,  and  may  detail  or  appoint 
officers  for  that  purpose.  The  Secretary  of  the  Treasury  shall 
make  such  rules  and  regulations  as  are  necessary  to  be  observed 
by  vessels  at  the  port  of  departure  and  on  the  voyage,  where  such 
vessels  sail  from  any  foreign  port  or  place  to  any  port  or  place  in 
the  United  States,  to  secure  the  best  sanitary  condition  of  such 
vessel,  her  cargo,  passengers,  and  crew ;  which  shall  be  published 
and  communicated  to  and  enforced  by  the  consular  officers  of  the 
United  States.  None  of  the  penalties  herein  imposed  shall  attach  to 
any  vessel  or  owner  or  officer  thereof  until  a  copy  of  this  act,  with 
the  rules  and  regulations  made  in  pursuance  thereof,  has  been 
posted  up  in  the  office  of  the  consul  or  other  consular  officer  of 
the  United  States  for  ten  days,  in  the  port  from  which  said  vessel 
sailed  ;  and  the  certificate  of  such  consul  or  consular  officer  over 
his  official  signature  shall  be  competent  evidence  of  such  posting 
in  any  court  of  the  United  States. 

Sec.  4.  That  it  shall  be  the  duty  of  the  Supervising  Surgeon- 
General  of  the  Marine-Hospital  Service,  under  the  direction  of 
the  Secretary  of  the  Treasury,  to  perform  all  the  duties  in  respect 
to  quarantine  and  quarantine  regulations  which  are  provided  for 
by  this  act,  and  to  obtain  information  of  the  sanitary  condition 
of  foreign  ports  and  places  from  which  contagious  and  infectious 
diseases  are  or  may  be  imported  into  the  United  States,  and  to 
this  end  the  consular  officers  of  the  United  States  at  such  ports 
and  places  as  shall  be  designated  by  the  Secretary  of  the  Treas- 
ury shall  make  to  the  Secretary  of  the  Treasury  weekly  reports  of 
the  sanitary  condition  of  the  ports  and  places  at  which  they  are 
respectively  stationed,  according  to  such  forms  as  the  Secretary 
of  the  Treasury  shall  prescribe ;  and  the  Secretary  of  the  Treas- 
ury shall  also  obtain,  through  all  sources  accessible,  including 
State  and  municipal  sanitary   authorities  throughout  the  United 


464  QUARANTINE. 

States,  weekly  reports  of  the  sanitary  condition  of  ports  and 
places  within  the  United  States,  and  shall  prepare,  publish,  and 
transmit  to  collectors  of  customs  and  to  State  and  municipal 
health  officers  and  other  sanitarians  weekly  abstracts  of  the  con- 
sular sanitary  reports  and  other  pertinent  information  received  by 
him,  and  shall  also,  as  far  as  he  may  be  able,  by  means  of  the 
voluntary  cooperation  of  State  and  municipal  authorities,  of  public 
associations,  and  private  persons,  procure  information  relating  to 
the  climatic  and  other  conditions  affecting  the  public  health,  and 
shall  make  an  annual  report  of  his  operations  to  Congress,  with 
such  recommendations  as  he  may  deem  important  to  the  public 
interests. 

Sec.  5.  That  the  Secretary  of  the  Treasury  shall  from  time  to 
time  issue  to  the  consular  officers  of  the  United  States  and  to  the 
medical  officers  serving  at  any  foreign  port,  and  otherwise  make 
publicly  known,  the  rules  and  regulations  made  by  him,  to  be 
used  and  complied  with  by  vessels  in  foreign  ports,  for  securing 
the  best  sanitary  condition  of  such  vessels,  their  cargoes,  passen- 
gers, and  crew,  before  their  departure  for  any  port  in  the  United 
States,  and  in  the  course  of  the  voyage  ;  and  all  such  other  rules 
and  regulations  as  shall  be  observed  in  the  inspection  of  the 
same  on  the  arrival  thereof  at  any  quarantine  station  at  the  port 
of  destination,  and  for  the  disinfection  and  isolation  of  the  same, 
and  the  treatment  of  cargo  and  persons  on  board,  so  as  to  pre- 
vent the  introduction  of  cholera,  yellow  fever,  or  other  contagious 
or  infectious  diseases ;  and  it  shall  not  be  lawful  for  any  vessel 
to  enter  said  port  to  discharge  its  cargo,  or  land  its  passengers, 
except  upon  a  certificate  of  the  health  officer  at  such  quarantine 
station  certifying  that  said  rules  and  regulations  have  in  all 
respects  been  observed  and  complied  with,  as  well  on  his  part 
as  on  the  part  of  the  said  vessel  and  its  master,  in  respect  to 
the  same  and  to  its  cargo,  passengers,  and  crew;  and  the  master 
of  every  such  vessel  shall  produce  and  deliver  to  the  collector  of 
customs  at  said  port  of  entry,  together  with  the  other  papers  of 
the  vessel,  the  said  bills  of  health  required  to  be  obtained  at  the 
port  of  departure  and  the  certificate  herein  required  to  be  obtained 
from  the  health  officer  at  the  port  of  entry  ;  and  that  the  bills 
of  health  herein  prescribed  shall  be  considered  as  part  of  the 
ship's  papers,  and  when  duly  certified  to  by  the  proper  consular 
officer  or  other  officer  of  the  United  States,  over  his  official  signa- 
ture and  seal,  shall  be  accepted  as  evidence  of  the  statements 
therein  contained  in  any  court  of  the  United  States. 

Sec.  6.  That  on  the  arrival  of  an  infected  vessel  at  any  port 
not  provided  with  proper  facilities  for  treatment  of  the  same, 
the  Secretary  of  the  Treasury  may  remand  said  vessel,  at  its  own 
expense,  to  the  nearest  national  or  other  quarantine  station, 
where  accommodations  and  appliances  are  provided  for  the  neces- 
sary disinfection  and  treatment  of  the  vessel,  passengers,  and 
cargo ;  and  after  treatment  of  any  infected  vessel  at  a  national 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  465 

quarantine  station,  and  after  certificate  shall  have  been  given  by 
the  United  States  quarantine  officer  at  said  station  that  the  vessel, 
cargo,  and  passengers  are  each  and  all  free  from  infectious  disease, 
or  danger  of  conveying  the  same,  said  vessel  shall  be  admitted 
to  entry  to  any  port  of  the  United  States  named  within  the  cer- 
tificate. But  at  any  ports  where  sufficient  quarantine  provision 
has  been  made  by  State  or  local  authorities  the  Secretary  of  the 
Treasury  may  direct  vessels  bound  for  said  ports  to  undergo  quar- 
antine at  said  State  or  local  station. 

Sec.  7.  That  whenever  it  shall  be  shown  to  the  satisfaction  of 
the  President  that  by  reason  of  the  existence  of  cholera  or  other 
infectious  or  contagious  diseases  in  a  foreign  country  there  is 
serious  danger  of  the  introduction  of  the  same  into  the  United 
States,  and  that  notwithstanding  the  quarantine  defence  this 
danger  is  so  increased  by  the  introduction  of  persons  or  property 
from  such  country  that  a  suspension  of  the  right  to  introduce 
the  same  is  demanded  in  the  interest  of  the  public  health,  the 
President  shall  have  power  to  prohibit,  in  whole  or  in  part,  the 
introduction  of  persons  and  property  from  such  countries  or 
places  as  he  shall  designate  and  for  such  period  of  time  as  he  may 
deem  necessary. 

Sec.  8.  That  whenever  the  proper  authorities  of  a  State  shall 
surrender  to  the  United  States  the  use  of  the  buildings  and  dis- 
infecting apparatus  at  a  State  quarantine  station  the  Secretary  of 
the  Treasury  shall  be  authorized  to  receive  them  and  to  pay  a 
reasonable  compensation  to  the  State  for  their  use,  if,  in  his 
opinion,  they  are  necessary  to  the  United  States. 

Sec.  9.  That  the  act  entitled  "  An  act  to  prevent  the  introduc- 
tion of  infectious  or  contagious  diseases  into  the  United  States, 
and  to  establish  a  national  board  of  health,"  approved  March  3, 
1879,  be,  and  the  same  is  hereby,  repealed.  And  the  Secretary 
of  the  Treasury  is  directed  to  obtain  possession  of  any  property, 
furniture,  books,  paper,  or  records  belonging  to  the  United 
States  which  are  not  in  the  possession  of  an  officer  of  the  United 
States  under  the  Treasury  Department  which  were  formerly  in  the 
use  of  the  National  Board  of  Health  or  any  officer  or  employe 
thereof. 

[Act  of  Congress,  approved  August  i8,  1894.] 

AN  ACT  to  amend  section  two  of  the  act  approved  February  fifteenth,  eigh- 
teen hundred  and  ninety-three,  entitled  "  An  act  granting  additional  quar- 
antine powers  and  imposing  additional  duties  upon  the  Marine-Hospital 
Service." 

Be  it  enacted  by  the  Seriate  and  House  of  Representatives  of  the 
Uiited  States  of  America  in  Congress  assembled,  That  section 
two  of  the  act  approved  February  fifteenth,  eighteen  hundred  and 
ninety-three,  entitled  "An  act  granting  additional  quarantine 
powers  and  imposing  additional  duties  upon  the  Marine-Hospital 
Service,"  is  hereby  amended  by  adding  to  the  end  of  said  section 
the  following  : 

30 


466  QUARANTINE. 

"The  provisions  of  this  section  shall  not  apply  to  vessels  plying 
between  foreign  ports  on  or  near  the  frontiers  of  the  United 
States  and  ports  of  the  United  States  adjacent  thereto ;  but  the 
Secretary  of  the  Treasury  is  hereby  authorized,  when,  in  his 
discretion,  it  is  expedient  for  the  preservation  of  the  public 
health,  to  establish  regulations  governing  such  vessels." 

REVISED    STATUTES. 

Sec.  4794.  There  shall  be  purchased  or  erected,  under  the 
orders  of  the  President,  suitable  warehouses,  with  wharves  and 
inclosures,  where  merchandise  may  be  unladen  and  deposited 
from  any  vessel  which  shall  be  subject  to  a  quarantine  or  other 
restraint,  pursuant  to  the  health  laws  of  any  State,  at  such  con- 
venient places  therein  as  the  safety  of  the  public  revenue  and 
the  observance  of  such  health  laws  may  require. 

Sec.  4795-  Whenever  the  cargo  of  a  vessel  is  unladen  at  some 
other  place  than  the  port  of  entry  or  delivery  under  the  fore- 
going provisions,  all  the  articles  of  such  cargo  shall  be  deposited, 
at  the  risk  of  the  parties  concerned  therein,  in  such  public  or 
other  warehouses  or  inclosures  as  the  collector  shall  designate, 
there  to  remain  under  the  joint  custody  of  such  collector  and 
of  the  owner,  or  master,  or  other  person  having  charge  of  such 
vessel,  until  the  same  are  entirely  unladen  or  discharged,  and 
until  the  articles  so  deposited  may  be  safely  removed  without 
contravening  such  health  laws.  And  when  such  removal  is  al- 
lowed, the  collector  having  charge  of  such  articles  may  grant 
permits  to  the  respective  owners  or  consignees,  their  factors  or 
agents,  to  receive  all  merchandise  which  has  been  entered,  and 
the  duties  accruing  upon  which  have  been  paid,  upon  the  pay- 
ment by  them  of  a  reasonable  rate  of  storage  ;  which  shall  be 
fixed  by  the  Secretary  of  the  Treasury  for  all  public  warehouses 
and  inclosures. 

Sec.  4796.  The  Secretary  of  the  Treasury  is  authorized,  when- 
ever a  conformity  to  such  quarantine  and  health  laws  requires 
it,  and  in  respect  to  vessels  subject  thereto,  to  prolong  the  terms 
limited  for  the  entry  of  the  same  and  the  report  or  entry  of  their 
cargoes,  and  to  vary  or  dispense  with  any  other  regulations  ap- 
plicable to  such  reports  or  entries.  No  part  of  the  cargo  of  any 
vessel  shall,  however,  in  any  case  be  taken  out  or  unladen  there- 
from otherwise  than  is  allowed  by  law,  or  according  to  the 
regulations  hereinafter  established. 

Sec.  4797-  Whenever,  by  the  prevalence  of  any  contagious  or 
epidemic  disease  in  or  near  the  place  by  law  established  as  the 
port  of  entry  for  any  collection  district,  it  becomes  dangerous 
or  inconvenient  for  the  officers  of  the  revenue  employed  therein 
to  continue  the  discharge  of  their  respective  offices  at  such  port, 
the  Secretary  of  the  Treasury,  or,  in  his  absence,  the  First  Comp- 
troller,   may    direct  the  removal  of   the  officers  of  the  revenue 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  467 

from  such  port  to  any  other  more  convenient  place  within  or  as 
near  as  may  be  to  such  collection  district.  And  at  such  place 
such  officers  may  exercise  the  same  powers  and  shall  be  liable 
to  the  same  duties,  according  to  existing  circumstances,  as  in 
the  port  or  district  established  by  law.  Public  notice  of  any 
such  removal  shall  be  given  as  soon  as  may  be. 

Sec.  4798.  In  case  of  the  prevalence  of  a  contagious  or  epi- 
demic disease  at  the  seat  of  Government,  the  President  may 
permit  and  direct  the  removal  of  any  or  all  the  public  offices  to 
such  other  place  or  places  as  he  shall  deem  most  safe  and  con- 
venient for  conducting  the  public  business. 

Sec.  4799.  Whenever,  in  the  opinion  of  the  Chief  Justice,  or, 
in  case  of  his  death  or  inability,  of  the  senior  associate  justice, 
of  the  Supreme  Court,  a  contagious  or  epidemic  sickness  shall 
render  it  hazardous  to  hold  the  next  stated  session  of  the  court  at 
the  seat  of  Government,  the  chief  or  such  associate  justice  may 
issue  his  order  to  the  marshal  of  the  Supreme  Court,  directing 
him  to  adjourn  the  next  session  of  the  court  to  such  other  place 
as  such  justice  deems  convenient.  The  marshal  shall  thereupon 
adjourn  the  court  by  making  publication  thereof  in  one  or  more 
public  papers  printed  at  the  seat  of  Government  from  the  time  he 
shall  receive  such  order  until  the  time  by  law  prescribed  for  com- 
mencing the  session.  The  several  circuit  and  district  judges 
shall,  respectively,  under  the  same  circumstances,  have  the  same 
power,  by  the  same  means,  to  direct  adjournments  of  the  several 
circuit  and  district  courts  to  some  convenient  place  within  their 
districts,  respectively. 

Sec.  4800.  The  judge  of  any  district  court  within  whose  dis- 
trict any  contagious  or  epidemic  disease  shall  at  any  time  prevail, 
so  as,  in  his  opinion,  to  endanger  the  lives  of  persons  confined  in 
the  prison  of  such  district,  in  pursuance  of  any  law  of  the  United 
States,  may  direct  the  marshal  to  cause  the  persons  so  confined  to 
be  removed  to  the  next  adjacent  prison  where  such  disease  does 
not  prevail,  there  to  be  confined  until  they  may  safely  be  removed 
back  to  the  place  of  their  first  confinement.  Such  removals  shall 
be  at  the  expense  of  the  United  States. 

Sec.  4263.  The  master  oi  anv  vessel  employed  in  transporting 
passengers  between  the  United  States  and  Europe  is  authorized  to 
maintain  good  discipline  and  such  habits  of  cleanliness  among 
the  passengers  as  will  tend  to  the  preservation  and  promotion  of 
health,  and  to  that  end  he  shall  cause  such  regulations  as  he  may 
adopt  for  this  purpose  to  be  posted  up,  before  sailing,  on  board 
such  vessel,  in  a  place  accessible  to  such  passengers,  and  shall 
keep  the  same  so  posted  up  during  the  voyage.  Such  master 
shall  cause  the  apartments  occupied  by  such  passengers  to  be 
kept  at  all  times  in  a  clean,  healthy  state  :  and  the  owners  oi 
every  such  vessel  so  employed  are  required  to  construct  the 
decks  and  all  parts  of  the  apartments  so  that  they  can  be  thor- 
oughly cleansed,  and  also  to  provide  a  safe,  convenient  privy,  or 


468  QUARANTINE. 

water-closet,  for  the  exclusive  use  of  every  one  hundred  such 
passengers.  The  master  shall  also,  when  the  weather  is  such  that 
the  passengers  can  not  be  mustered  on  deck  with  their  bedding, 
and  at  such  other  times  as  he  may  deem  necessary,  cause  the 
deck  occupied  by  such  passengers  to  be  cleansed  with  chlorid 
of  lime  or  some  other  equally  efificient  disinfecting  agent.  And 
for  each  neglect  or  violation  of  any  of  the  provisions  of  this 
section  the  master  and  owner  of  any  such  vessel  shall  be  sever- 
ally liable  to  the  United  States  in  a  penalty  of  fifty  dollars,  to 
be  recovered  in  any  circuit  or  district  court  within  the  jurisdic- 
tion of  which  such  vessel  may  arrive  or  from  which  she  is  about 
to  depart,  or  at  any  place  where  the  owner  or  master  may  be 
found. 

[Extract  from  act  August  i,  1888.] 

Whenever  any  person  shall  trespass  upon  the  grounds  belong- 
ing to  any  quarantine  reservation,  such  person,  trespassing,  shall, 
upon  conviction  thereof,  pay  a  fine  of  not  more  than  three  hun- 
dred dollars,  or  be  sentenced  to  imprisonment  for  a  period  of 
not  more  than  thirty  days,  or  shall  be  punished  by  both  fine  and 
imprisonment,  at  the  discretion  of  the  court.  And  it  shall  be 
the  duty  of  the  United  States  Attorney  in  the  district  where  the 
misdemeanor  shall  have  been  committed  to  take  immediate  cog- 
nizance of  the  offence,  upon  report  made  to  him  by  any  medical 
officer  of  the  Marine- Hospital  Service,  or  by  any  officer  of  the 
customs  service,  or  by  any  State  officer  acting  under  authority 
of  section  five  of  said  act. 


AN  ACT  TO  Prevent  the  Introduction  of  Contagious  Diseases  from 
One  State  to  Another  and  for  the  Punishment  of  Certain 
Offences. 

[Act  March  27,  1890.] 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  asseinbled,  That  whenever  it 
shall  be  made  to  appear  to  the  satisfaction  of  the  President  that 
cholera,  yellow  fever,  small-pox,  or  plague  exists  in  any  State  or 
Territory,  or  in  the  District  of  Columbia,  and  that  there  is  danger 
of  the  spread  of  such  disease  into  other  States,  Territories,  or  the 
District  of  Columbia,  he  is  hereby  authorized  to  cause  the  Secre- 
tary of  the  Treasury  to  promulgate  such  rules  and  regulations  as  in 
his  judgment  may  be  necessary  to  prevent  the  spread  of  such  dis- 
ease from  one  State  or  Territory  into  another,  or  from  any  State 
or  Territory  into  the  District  of  Columbia,  or  from  the  District  of 
Columbia  into  any  State  or  territory,  and  to  employ  such  inspec- 
tors and  other  persons  as  may  be  necessary  to  execute  such  regula- 
tions to  prevent  the  spread  of  such  disease.  The  said  rules  and 
regulations  shall  be  prepared  by  the  Supervising  Surgeon-General 
of  the  Marine-Hospital  Service  under  the  direction  of  the  Secre- 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  469 

tary  of  the  Treasury.  And  any  person  who  shall  willfully  violate 
any  rule  or  regulation  so  made  and  promulgated  shall  be  deemed 
guilty  of  a  misdemeanor,  and  upon  conviction  shall  be  punished  by 
a  fine  of  not  more  than  five  hundred  dollars,  or  imprisonment  for 
not  more  than  two  years,  or  both,  in  the  discretion  of  the  court. 

Sec.  2.  That  any  officer,  or  person  acting  as  an  officer,  or  agent 
of  the  United  States  at  any  quarantine  station,  or  other  person 
employed  to  aid  in  preventing  the  spread  of  such  disease,  who 
shall  willfully  violate  any  of  the  quarantine  laws  of  the  United 
States,  or  any  of  the  rules  and  regulations  made  and  promulgated 
by  the  Secretary  of  the  Treasury  as  provided  for  in  Section  i  of 
this  act,  or  any  lawful  order  of  his  superior  officer  or  officers,  shall 
be  deemed  guilty  of  a  misdemeanor,  and  upon  conviction  shall  be 
punished  by  a  fine  of  not  more  than  three  hundred  dollars  or 
imprisonment  for  not  more  than  one  year,  or  both,  in  the  discre- 
tion of  the  court. 

Sec.  3.  That  when  any  common  carrier  or  officer,  agent,  or 
employe  of  any  common  carrier  shall  Avillfully  violate  any  of  the 
quarantine  laws  of  the  United  States,  or  the  rules  and  regulations 
made  and  promulgated  as  provided  for  in  Section  i  of  this  act, 
such  common  carrier,  officer,  agent,  or  employe  shall  be  deemed 
guilty  of  a  misdemeanor,  and  shall,  on  conviction,  be  punished 
by  a  fine  of  not  more  than  five  hundred  dollars,  or  imprisonment 
for  not  more  than  two  years,  or  both,  in  the  discretion  of  the 
court. 

AN  ACT  TO  Amend  "An  Act  Granting  Additional  Quarantine 
Power  and  Imposing  Additional  Duties  upon  the  Marine  Hospital 
Service, '■'  Approved  February  Fifteenth,  Eighteen  Hundred  and 
Ninety-three. 

[Act  March  2,  1901.] 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  assembled,  That  an  Act 
granting  additional  quarantine  powers  and  imposing  additional 
duties  upon  the  Marine-Hospital  Service,  approved  February  fif- 
teenth, eighteen  hundred  and  ninety-three,  be  amended  by  addi- 
tion of  the  following  sections  : 

''  Sec.  10.  That  the  Supervising  Surgeon -General,  with  the 
approval  of  the  Secretary  of  the  Treasury,  is  authorized  to  desig- 
nate and  mark  the  boundaries  of  the  quarantine  grounds  and 
quarantine  anchorages  for  vessels  which  are  reserved  for  use  at 
each  United  States  quarantine  station  ;  and  any  vessel  or  officer 
of  any  vessel  or  other  person,  other  than  State  or  municipal 
health  or  quarantine  officers,  trespassing  or  otherwise  entering 
upon  such  grounds  or  anchorages  in  disregard  of  the  quarantine 
rules  and  regulations,  or  without  permission  of  the  officer  in  charge 
of  such  station,  shall  be  deemed  guilty  of  a  misdemeanor  and 
subject  to  arrest,  and  upon  conviction  thereof  be  punished  by  a 
fine  of  not  more  than  three  hundred  dollars  or  imprisonment  for 


470  QUARANTINE. 

not  more  than  one  year,  or  both,  in  the  discretion  of  the  court. 
Any  master  or  owner  of  any  vessel,  or  any  person  violating  any 
provision  of  this  Act  or  any  rule  or  regulation  made  in  accordance 
with  this  Act,  relating  to  inspection  of  vessels  or  relating  to  the 
prevention  of  the  introduction  of  contagious  or  infectious  dis- 
eases, or  any  master,  owner,  or  agent  of  any  vessel  making  a  false 
statement  relative  to  the  sanitary  condition  of  said  vessel  or  its 
contents  or  as  to  the  health  of  any  passenger  or  person  thereon, 
shall  be  deemed  guilty  of  a  misdemeanor  and  subject  to  arrest, 
and  upon  conviction  thereof  be  punished  by  a  fine  of  not  more 
than  five  hundred  dollars  or  imprisonment  for  not  more  than  one 
year,  or  both,  in  the  discretion  of  the  court. 

"  Sec.  II.  That  any  vessel  sailing  from  any  foreign  port  without 
the  bill  of  health  required  by  section  two  of  this  Act,  and  arriv- 
ing within  the  limits  of  any  collection  district  of  the  United 
States,  and  not  entering  or  attempting  to  enter  any  port  of  the 
United  States,  shall  be  subject  to  such  quarantine  measures  as 
shall  be  prescribed  by  regulations  of  the  Secretary  of  the  Treasury, 
and  the  cost  of  such  measures  shall  be  a  lien  on  said  vessel,  to  be 
recovered  by  proceedings  in  the  proper  district  court  of  the 
United  States  and  in  the  manner  set  forth  above  as  regards  vessels 
from  foreign  ports  without  bills  of  health  and  entering  any  port 
of  the  United  States. 

"  Sec.  12.  That  the  medical  officers  of  the  United  States,  duly 
clothed  with  authority  to  act  as  quarantine  officers  at  any  port  or 
place  within  the  United  States,  and  when  performing  the  said 
duties,  are  hereby  authorized  to  take  declarations  and  administer 
oaths  in  matters  pertaining  to  the  administration  of  the  quarantine 
laws  and  regulations  of  the  United  States." 

AN  ACT  TO  Further  Protect  the  Public  Health  and  Make  More 
Effective  the  National  Quarantine. 

[Approved,  June  ig,  igo6.] 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  assembled,  That  the  Secre- 
tary of  the  Treasury  shall  have  the  control,  direction,  and  man- 
agement of  all  quarantine  stations,  grounds,  and  anchorages 
established  by  authority  of  the  United  States,  and  as  soon  as 
practicable  after  the  approval  of  this  Act  shall  select  and  desig- 
nate such  suitable  places  for  them  and  establish  the  same  at 
such  points  on  or  near  the  coast  line  of  the  United  States  or  the 
border  of  the  United  States  and  a  foreign  country,  as  in  his 
judgment  are  best  suited  for  the  same  and  necessary  to  pre- 
vent the  introduction  of  yellow  fever  into  the  United  States, 
and,  in  his  discretion,  he  may  also  establish  at  the  group  of 
islands  known  as  the  Dry  Tortugas,  at  the  western  end  of  the 
Florida  reef,  and  at  such  other  point  or  points  on  or  near  the 
coast  line  of  the  United  States  (not  to  exceed  four  in  the  aggre- 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   471 

gate)  as  he  deems  necessary,  quarantine  grounds,  stations,  and 
anchorages,  whereat  or  whereto  infected  vessels  bound  for  any 
port  in  the  United  States  may  be  detained  or  sent  for  the  pur- 
pose of  being  disinfected,  having  their  cargoes  disinfected  and 
discharged,  if  necessary,  and  their  sick  treated  in  hospitals  until 
all  danger  of  infection  or  contagion  from  such  vessels,  their 
cargoes,  passengers,  or  crews  has  been  removed. 

Sec.  2.  That  in  cases  in  which  the  title  to  the  land  and  water 
so  selected  and  designated  is  in  the  United  States  it  shall  be  the 
duty  of  the  department,  bureau,  or  official  of  the  United  States 
having  custody  or  possession  of  such  land  and  water,  or  any  part 
thereof,  not  used  by  the  Government  for  other  purposes  desig- 
nated by  law,  or  possession  of  said  Dry  Tortugas  Islands,  on 
demand  of  the  Secretarv^  of  the  Treasury,  to  deliver  the  same 
into  his  custody  and  possession  for  the  use  of  the  Public  Health 
and  Marine-Hospital  Service,  evidencing  such  deliver^'  by  a 
suitable  instrument  in  writing  to  be  delivered  to  the  Secretary 
of  the  Treasury.  That  in  cases  in  which  the  title  to  such  land 
and  water,  or  any  part  thereof,  is  in  any  other  owner  than  the 
United  States  it  shall  be  the  duty  of  the  Secretary  of  the  Treasur\^ 
to  secure  the  title  and  possession  of  the  same  to  the  United 
States  for  the  use  of  the  Public  Health  and  Marine-Hospital 
Ser^dce  of  the  United  States,  by  purchase  at  a  reasonable  price, 
if  possible;  but  if,  in  his  judgment,  the  price  demanded  for  such 
property  be  excessive,  he  is  hereby  authorized  to  apply  to  the 
Attorney-General  of  the  United  States  to  cause  to  be  instituted, 
in  the  proper  tribunal,  condemnation  proceedings  in  the  name 
of  the  United  States  for  the  purpose  of  acquiring  for  the  United 
States  the  title  and  possession  of  such  land  and  water,  and  said 
Attorney- General  shall,  as  soon  as  possible  after  such  application 
by  the  Secretars-  of  the  Treasures  cause  such  proceedings  to  be 
instituted  and  conducted  to  a  conclusion,  and  the  custody  and 
possession  of  such  land  and  w^ater,  when  duly  acqmred  in  ac- 
cordance v-ith  the  award  made  in  such  condemnation  proceed- 
ings, shall  be  delivered  to  the  Secretarv-  of  the  Treasur\'  for  the 
use  of  the  Public  Health  and  Marme-Hospital  Ser\dce. 

Sec.  3.  That  on  acquiring  possession  of  any  land  and  water 
in  accordance  with  the  provisions  of  this  Act  for  the  purpose  of 
establishing  thereat  a  quarantine  station  and  anchorage,  the 
Secretary  of  the  Treasury  shall  cause  to  be  published  in  such 
newspapers  as  he  may  think  proper,  once  a  week  for  four  suc- 
cessive weeks,  a  notice  of  the  selection  and  designation  of  such 
places  for  quarantine  stations  and  anchorages,  with  a  description 
of  the  boundaries  of  such  quarantine  stations  and  anchorages, 
and  such  rules  and  regulations  as  he  shall  adopt  and  promulgate, 
requiring  vessels  with  yellow  fever  among  their  passengers  or 
crews  to  go  to  specified'  quarantine  stations  and  anchorages,  to 
be  dealt  with  there  before  visiting  any  port  of  the  United  States, 


472  QUARANTINE. 

He  shall  establish  at  such  quarantine  stations  and  anchorages 
all  necessary  instrumentalities  for  disinfecting  vessels  and  their 
cargoes,  and  where  the  same  shall  be  required  shall  erect  the 
necessary  hospital  buildings  and  install  the  necessary  furniture 
and  fittings  for  receiving  and  treating  the  sick  among  the  passen- 
gers and  crews  of  vessels  going  to  such  quarantine  stations  and 
anchorages,  and  provide  for  the  separation  of  those  among  their 
passengers  and  crews  who  are  suffering  from  yellow  fever  from 
those  who  are  in  good  health,  and  shall  further  provide  for  doing 
all  things  necessary  to  eradicate  such  disease  from  such  vessels, 
their  cargoes,  passengers,  and  crews. 

Sec.  4.  That  any  vessel,  or  any  officer  of  any  vessel,  or  other 
person  other  than  State  health  or  quarantine  officers,  entering 
within  the  limits  of  any  quarantine  grounds  and  anchorages, 
or  any  quarantine  station  and  anchorage,  or  departing  therefrom, 
in  disregard  of  the  quarantine  rules  and  regulations  or  without 
the  permission  of  the  officer  in  charge  of  such  quarantine  ground 
and  anchorage,  or  of  such  quarantine  station  and  anchorage, 
shall  be  deemed  guilty  of  a  misdemeanor,  and  upon  conviction 
thereof  shall  be  punished  by  a  fine  of  not  more  than  three  hundred 
dollars  or  by  imprisonment  for  not  more  than  one  year,  or  both, 
in  the  discretion  of  the  court.  That  any  master  or  owner  of  any 
vessel  violating  any  provision  of  this  Act,  or  any  provision  of  an 
Act  entitled  "An  Act  granting  additional  powers  and  imposing 
additional  duties  on  the  Marine-Hospital  Service,"  approved 
February  fifteenth,  eighteen  hundred  and  ninety-three,  or  violat- 
ing any  rule  or  regulation  made  in  accordance  with  this  Act  or 
said  Act  of  February  fifteenth,  eighteen  hundred  and  ninety- 
three,  relating  to  the  inspection  of  vessels,  or  to  the  prevention  of 
the  introduction  of  contagious  or  infectious  diseases  into  the 
United  States,  or  any  master,  owner,  or  agent  of  any  vessel  mak- 
ing a  false  statement  relative  to  the  sanitary  condition  of  such 
vessel  or  its  contents,  or  as  to  the  health  of  any  passenger  or 
person  thereon  shall  be  deemed  guilty  of  a  misdemeanor,  and  on 
conviction  thereof  shall  be  punished  by  a  fine  of  not  more  than 
five  hundred  dollars  or  imprisonment  for  not  more  than  one 
year,  or  both,  in  the  discretion  of  the  court. 

Sec.  5.  That  in  any  place  where  a  quarantine  station  and 
plant  is  already  established  by  State  or  local  authorities  it  shall 
be  the  duty  of  the  Secretary  of  the  Treasury,  before  selecting  and 
designating  a  quarantine  station  and  grounds  and  anchorage 
for  vessels,  to  examine  such  established  stations  and  plants, 
with  a  view  of  obtaining  a  transfer  of  the  site  and  plants  to  the 
United  States,  and  whenever  the  proper  authorities  shall  be 
ready  to  transfer  the  same  or  surrender  the  use  thereof  to  the 
United  States,  the  Secretary  of  the  Treasury  is  authorized  to 
obtain  title  thereto  or  possession  and  use  thereof,  and  to  pay  a 
reasonable  compensation  therefor,  if,  in  his  opinion,  such  pur- 


QUARANTINE  LA  WS  OF  THE  UNITED  STA  TES.  473 

chase  or  use  will  be  necessary  to  the  United  States  for  quarantine 
purposes  and  the  quarantine  stations  established  by  authority 
of  this  Act  shall,  when  so  established,  be  used  to  prevent  the  in- 
troduction of  all  quarantinable  diseases. 

Sec.  6.  That  whenever  any  established  station,  or  any  land  or 
water,  or  any  part  thereof,  shall  be  acquired  by  the  United 
States  under  the  provisions  of  this  Act,  jurisdiction  over  the 
same  shall  be  ceded  to  the  United  States  by  any  State  in  which 
the  same  is  situated  before  any  compensation  therefor  shall  be 
paid. 

Sec.  7.  That  the  sum  of  five  hundred  thousand  dollars,  or  so 
much  thereof  as  may  be  necessary,  is  hereby  appropriated, 
out  of  any  money  in  the  Treasury  not  otherwise  appropriated, 
for  the  purpose  of  carrying  into  effect  the  provisions  of  this 
Act,  as  well  as  for  the  purpose  generally  of  preventing  the  im- 
portation of  yellow  fever  and  other  quarantinable  diseases  into 
the  United  States,  and  for  the  further  purposes,  in  co-operation 
with  State  or  municipal  health  authorities,  of  eradicating  them 
shoiild  they  be  imported,  of  preventing  their  spread  from  one 
State  into  another  State,  and  of  destroying  their  causes. 

QUARANTINE   REGULATIONS. 

QUARANTINABLE  DISEASES. 

1.  For  the  purpose  of  these  regulations  the  quarantinable  dis- 
eases are  cholera,  yellow  fever,  small-pox,  typhus  fever,  leprosy, 
and  plague. 

FOREIGN  REGULATIONS. 

Quarantine  Regulations  to  be   Observed  at  Foreign  Ports  and  at  Ports  in 
the  Possessions  and  Dependencies  of  the  United  States. 

Bills  of  Health. 

2.  Masters  of  vessels  departing  from  any  foreign  port,  or  from 
any  port  in  the  possessions  or  other  dependencies  of  the  United 
States  for  a  port  in  the  United  States  or  its  possessions  or  other 
dependencies,  must  obtain  a  bill  of  health,  in  duplicate,  signed  by 
the  proper  officer  or  officers  of  the  United  States  as  provided  for 
by  law,  except  as  provided  for  in  paragraph  4! 

The  following  form  is  prescribed: 

[Form  No.  1937.] 
United  States  of  America. 

ORIGINAL  bill   OF  HEALTH. 

I, (the  person  authorized  to  issue  the  bill,  at  the  port  of ),  do 

hereby  state  that  the  vessel  hereinafter  named  clears  from  the  port  of 

under  the  following  circumstances: 


474 


QUARANTINE. 


Name  of  vessel, 


Nationality, 
net,    - 


Rig,  - 
Iron   or 


wood, 


Master, 


For  steerage  passengers. 


.     Tonnage,    gross. 

Number  of  compartments  for  cargo. 
For  crew, . 

Name  of  medical  officer, . 

Number  of  officers,  ;  of  crew,  including  petty  officers,  ;  of 

passengers,   first   cabin,   — ■ ;   second   cabin,   t\   steerage,   . 

Officers'  families, .     Total  number  of  persons  on  board, 


Passengers  destined  for  the  United  States, 

cabin,  steerage. 

Previous  port. 


first  cabin. 


second 


Number  of  cases  of  sickness,  and  character  of  same,  during  last  voyage. 


Number  of  cases  of  sickness,  and  character  of  same,  while  vessel  was  in 

this  port,  . 

Vessel  engaged  in trade,  and  plies  between and . 

Nature,  sanitary  history,  and  condition  of  cargo, . 

Source  and  wholesomeness  of  water  supply, . 

Source  and  wholesomeness  of  food  supply. 


Sanitary  history  and  health  of  officers  ancl  crew. 
Sanitary  history  and  health  of  passengers,  cabin. 


Sanitary  history  and  health  of  passengers,  steerage, 

Sanitary  history  and  condition  of  their  effects, . 

Location  of  vessel  while  in  port — wharf, ;  open  bay, 

from  shore, . 

Time  vessel  was  in  port. 


-;  distance 


Character  of  communication  with  shore, . 

Sanitary  condition  of  vessel, . 

Sanitary  measures,  if  any,  adopted  while  in  port, . 

Sanitary  condition  of  port  and  vicinity, . 

Prevailing  chseases  at  port  and  vicinity, . 

Malaria, deaths  during  month  of . 

Nmnber  of  cases  and  deaths  from  the  following-named  diseases  during  the 
past  two  weeks,  ending . 


Diseases. 


Yellow  fever 

Asiatic  cholera 

Cholera  nostras  or  cholerine 

Small-pox 

Typhus  fever 

Plague 

Leprosy 


Number  of 
Deaths. 


Any  conditions  affecting  the  public  health  existing  in  the  port  of  departure 
or  vicinity  to  be  here  stated. 

When  there  are  no  cases  or  deaths,  entry  to  that  effect  must  be  made. 

I  certify  that  the  vessel  has  complied  with  the  Quarantine  Rules  and 
Regulations  made  under  the  act  of  February  15,  1893,  and  that  the  vessel 
leaves  this  port  bound  for ,  United  States  of  America,  via . 

Given  under  my  hand  and  seal  this day  of ,  191- 


[SEAL.] 


(Signature  of  consular  officer:) 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   475 

3.  Vessels  clearing  from  a  foreign  port  or  from  any  port  in  the 
possessions  or  other  dependencies  of  the  United  States  for  any 
port  in  the  United  States,  its  possessions  or  other  dependencies, 
and  entering  or  calling  at  intermediate  ports,  must  procure  at 
all  said  ports  a  supplemental  bill  of  health  in  duplicate  signed 
by  the  proper  ofl&cer  or  officers  of  the  United  States,  as  provided 
in  the  law.  If  a  quarantinable  disease  has  appeared  on  board 
the  vessel  after  leaving  the  original  port  of  departure,  or  other 
circumstances  presumably  render  the  vessel  infected,  the  supple- 
mental bill  of  health  should  be  withheld  until  such  sanitary 
measures  have  been  taken  as  are  necessary. 

The  following  form  is  prescribed: 

United  States  of  America. 


SUPPLEMENTAL   BILL   OF   HEALTH. 


Port  of 


Vessel 


bound  from 


to 


U.  S.  A. 


Sanitary  condition  of  port, . 

State  diseases  prevailing  at  port  and  in  surrounding  country, . 

Number  of  cases  and  the  deaths  from  the  follo\ving-named  diseases  during 
the  past  two  weeks: 


Dfseases. 


Number  of 
Cases. 


Number  of 
Deaths. 


Remarks.  (Any  condition  affecting  the  pub- 
lic health  existing  in  the  port  to  be  stated 
here.  When  there  are  no  cases  or  deaths, 
entry  to  that  effect  must  be  made.) 


Yellow  fever. .  .  . 

Asiatic  cholera, 
cholera  nostras, 
or  cholerine 

Small-pox...  . 

Typhus  fever. 

Plague. . . . 

Leprosy . .  . 


Number  and  sanitary  condition  of  passengers  and  crew  landed  at  this  port: 
First  cabin,  No. ;  sanitary  history  and  condition, . 


-;  sanitary  history  and  condition, 
-;  sanitary  history  and  condition, 


Second  cabin,  No. 

Steerage,  No. 

Crew,  No. ;  sanitary  condition  and  history. 

Note. — If  any  passenger  or  member  of  crew  disembarked  on  account  of 
sickness,  state  disease. 

Number  and  sanitary  condition  of  passengers  and  crew  taken  on  at  this 
port,  and  sanitary  condition  of  effects:  ' 

First  cabin,  No.  ;  sanitary  condition  and  history,  . 


Second  cabin,  No. 
Steerage,  No.  


sanitary  condition  and  history, 
-;  sanitary  condition  and  history, 


Nmnber  of  passengers  for  United  States; 
ond  cabin, steerage. 


first  cabin, 


476  QUARANTINE. 

Crew,  No. ;  sanitary  condition  and  history, . 

Sanitary  condition  of  effects, . 

Total  passengers  on  board, ;  total  crew  on  board, , 

Sanitary  measures,  if  any,  adopted  while  in  port, . 

Location  of  vessel  while  in  port — wharf, ;  open  bay, ;  distance 

from  shore,  . 

Time  vessel  was  in  port. 


Character  of  communication  with  shore, . 

Nature,  sanitary  history,  and  condition  of  cargo  taken  on  at  this  port, 


(Form  A  will  be  used  at  intermediate  ports  where 
the  vessel  does  not  enter  and  clear.) 


(Cancel  Form  A,  B,  or  C,  as  the  case  requires.) 
Form.  ^ 

A. — To  the  best  of  my  knowledge  and  belief — 

no    quarantinable    disease 
>     has      appeared      aboard 
B.— I  have  satisfied  myself  that—  I      ^™*^^  leaving  . 

(Form  B  will  be  used  at  intermediate  ports  where 
the  vessel  enters  and  clears.)  ) 

C. — Since  leaving the  following  quarantinable  disease  has  appeared  on 

board ,  and  I  certify  that  the  necessary  sanitary  measures  have  been 

taken. 

I  certify  also  that  with  reference  to  the  passengers,  effects,  and  cargo  taken 
on  at  this  port,  the  vessel  has  complied  with  the  rules  and  -regulations  made 
under  the  act  of  February  15,  1893. 

Given  tmder  my  hand  and  seal  this day  of ,  191 — . 

(Signature  of  consular  officer:) , 


4.  Under  the  act  of  Congress  approved  August  18,  1894,  ves- 
sels plying  between  Canadian  ports  on  the  St.  Croix  River,  the 
St.  Lawrence  River,  the  Niagara  River,  the  Detroit  River,  the  St. 
Clair  River,  and  the  St.  Mary's  River,  and  adjacent  ports  of  the 
United  States  on  the  same  waters;  also  vessels  plying  between 
Canadian  ports  on  the  following-named  lakes,  viz.,  Ontario,  Erie, 
St.  Clair,  Huron,  Superior,  Rainy  Lake,  Lake  of  the  Woods,  and 
Lake  Champlain,  and  ports  in  the  United  States;  also  vessels 
plying  between  Mexican  ports  on  the  Rio  Grande  River  and  adja- 
cent ports  in  the  United  States,  are  exempt  from  the  provisions 
of  section  2  of  the  act  granting  additional  quarantine  powers  and 
imposing  additional  duties  upon  the  Marine-Hospital  Service, 
approved  February  15,  1893,  which  requires  vessels  clearing  from 
a  foreign  port  for  a  port  in  the  United  States  to  obtain  from  the 
consular  or  medical  officer  a  bill  of  health.  During  the  preva- 
lence of  any  of  the  quarantinable  diseases  at  the  foreign  port  of 
departure,  vessels  above  referred  to  are  hereby  required  to  obtain 
from  the  consular  officer  of  the  United  States,  or  from  the  medical 
officer  of  the  United  States,  when  such  officer  has  been  detailed 
by  the  President  for  this  purpose,  a  bill  of  health,  or  a  supple- 
mental bill  of  health,  in  duplicate,  in  the  form  prescribed  by  the 
Secretary  of  the  Treasury. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   All 


FOREIGN  AND   INSULAR  REGULATIONS. 

INSPECTION  OF  \TSSELS  LEAVING  FOREIGN  PORTS  AND  PORTS  IN  THE 
POSSESSIONS  OR  OTHER  DEPENDENCIES  OF  THE  UNITED  STATES 
FOR  PORTS  JN  THE  UNITED  STATES  OR  ITS  POSSESSIONS  OR  OTHER 
DEPENDENCIES. 

5.  The  officer  issuing  the  bill  of  health  shall  satisfy  himself,  by 
inspection,  if  necessarv^  that  the  conditions  certified  to  therein  are 
true,  and  is  authorized,  in  accordance  with  the  law,  to  withhold 
the  bill  of  health  or  the  supplemental  bill  of  health  until  he  is 
satisfied  that  the  vessel,  the  passengers,  the  crew,  and  the  cargo 
have  complied  with  all  the  quarantine  laws  and  regulations  of  the 
United  States. 

6.  Inspection  is  required  of — 

(a)  AU  vessels  from  ports  at  which  cholera,  yellow  fever,  or 
plague  prevails,  or  at  which  small-pox  or  t}phus  fever  prevails  in 
epidemic  form. 

(6)  All  vessels  carr\'ing  steerage  passengers;  but  need  only 
include  the  inspection  of  such  passengers  and  their  living  apart- 
ments, if  sailing  from  a  healthy  port. 

7.  Inspection  of  the  vessel  is  such  an  examination  of  the  vessel, 
cargo,  passengers,  crew,  personal  effects  of  same,  uicluding  ex- 
amination of  manifests  and  other  papers,  food  and  water  supply, 
the  ascertainment  of  its  relations  ^\dth  the  shore,  the  manner  of 
loading  and  possibilities  of  invasion  by  small  animals  as  will 
enable  the  inspecting  officer  to  determine  if  these  regulations  have 
been  complied  with. 

8.  When  an  inspection  is  required,  it  should  be  made  by  day- 
light, as  late  as  practicable  before  sailing.  The  vessel  should  be 
inspected  before  the  passengers  go  aboard,  the  passengers  just 
before  embarkation,  and  the  crew  on  deck;  and  no  communica- 
tion shoiild  be  had  with  the  vessel  after  such  inspection  except  by 
permission  of  the  officer  issuing  the  bill  of  health. 

GENERAL   REQUIREMENTS    (FOREIGN   AND   INSULAR) 

9.  Vessels,  prior  to  storing  cargo  or  recei\dng  passengers? 
should  be  mechanically  clean  in  all  parts,  especially  the  hold, 
forecastle,  and  steerage. 

10.  Any  portions  of  the  vessel  liable  to  have  been  infected  by 
any  communicable  disease  should  be  disinfected  before  the 
issuance  of  the  bill  of  health. 

11.  The  air  space,  ventilation,  food  and  water  supply,  hospital 
accommodations,  and  all  other  matters  mentioned  therein  pro- 
motive of  the  health  and  comfort  of  the  passengers  must  be  in 
accordance  AA-ith  the  provisions  of  the  act  of  Congress  approved 


478  QUARANTINE. 

August  2,  1882,  entitled  "An  act  to  regulate  the  carriage  of  pas- 
sengers by  sea." 

12.  Street  sweepings,  city  cleanings,  or  anything  containing 
organic  refuse  should  not  be  taken  as  ballast  from  any  port. 

13.  Bedding,  upholstered  furniture,  soiled  wearing  apparel,  per- 
sonal effects,  and  secondhand  articles  of  a  similar  nature,  coming 
from  a  district  known  to  be  infected  with  cholera,  small-pox, 
typhus  fever,  or  as  to  the  origin  of  which  no  positive  evidence 
can  be  obtained,  and  which  the  consular  or  medical  officer  has 
reason  to  believe  are  infected,  should  be  disinfected  prior  to  ship- 
ment. In  the  case  of  typhus  fever,  the  destruction  of  vermin 
should  be  assured.  Articles  similar  to  the  above  mentioned,  if 
from  a  district  infected  by  plague,  should  be  inspected,  and,  if 
necessary,  disinfected  and  treated  to  destroy  vermin. 

14.  Articles  from  an  uninfected  district  shipped  through  an 
infected  port  may  be  accepted  without  restriction  if  not  ex- 
posed to  infection  in  transit. 

15.  Nothing  in  these  regulations  shall  be  construed  to  modify 
or  affect  in  any  way  any  existing  restrictions  promulgated  by  the 
Secretary  of  the  Treasury  at  the  instance  of  the  Secretary  of 
Agriculture,  regarding  the  importation  of  hides  of  neat  cattle. 

16.  Any  article  shipped  from  or  through  an  infected  port  or 
place,  and  which  the  consul  or  medical  officer  has  reason  to  be- 
lieve infected,  should  be  disinfected. 

17.  Any  article  presumably  infected,  which  cannot  be  disin- 
fected, should  not  be  shipped. 

18.  Passengers,  for  the  purposes  of  these  regulations,  are  di- 
vided into  two  classes,  cabin  and  steerage.^ 

19.  So  far  as  possible  passengers  should  avoid  embarking  at  a 
port  where  quarantinable  disease  prevails,  and  communication 
between  the  vessel  and  the  shore  should  be  reduced  to  a  minimum. 
In  such  a  port  the  personnel  of  the  vessel  should  remain  on  board 
during  their  stay. 

Vessels  carrying  passengers  from  any  port  where  quarantin- 
able disease  prevails  in  epidemic  form  shoiild  have  a  medical 
officer. 

20.  No  person  suffering  from  a  quarantinable  disease,  or  scarlet 
fever,  measles,  diphtheria,  or  other  communicable  disease,  should 
be  allowed  to  ship. 

21.  All  baggage  of  steerage  passengers  destined  for  the  United 
States  should  be  labeled.  If  the  baggage  is  in  good  sanitary 
condition,  the  label  shall  be  a  red  label  bearing  the  name  of  the 

1  The  sanitary  measures  applicable  to  second-cabin  pasengers  will  be  those 
designated  for  first-cabin  pasengers  or  for  steerage  passengers,  according  as  the 
arrangements  of  their  quarters  and  accommodations  aboard,  both  sanitary 
and  for  association,  class  them  in  the  opinion  of  the  inspecting  ofl&cer  with 
the  first  cabin  or  steerage. 


QUARANTINE  LA  WS  OF  THE  UNITED  STA  TES.    479 

port,  the  steamship  on  which  the  baggage  is  to  be  carried,  the 
word  "passed"  in  large  t}^e,  the  date  of  inspection,  and  the  seal 
or  stamp  of  the  consular  or  medical  ofificer  of  the  United  States. 
All  baggage  that  has  been  disinfected  shall  bear  a  yellow  label, 
upon  which  shall  be  printed  the  name  of  the  port,  the  steamship 
upon  which  the  baggage  is  to  be  carried,  the  word  "disinfected" 
in  large  type,  the  date  of  disinfection,  and  the  seal  or  stamp  of 
the  consular  or  medical  of&cer  of  the  United  States.  It  is  under- 
stood, and  it  will  be  so  printed  on  the  blank,  that  the  label  is  not 
valid  unless  bearing  the  consular  or  medical  officer's  stamp  or 
seal. 

22.  Each  steerage  passenger  shall  be  furnished  with  an  inspec- 
tion card.  (See  p.  468.)  This  card,  stamped  by  the  consular  or 
medical  officer,  is  to  be  issued  to  every  member  of  a  family  as 
well  as  to  the  head  thereof. 

23.  Passengers  and  crews,  merchandise,  and  baggage,  prior  to 
shipment  at  a  non-infected  port,  but  coming  from  an  infected 
locality,  should  be  subject  to  the  same  restrictions  as  are  im- 
posed at  an  infected  port. 

SPECIAL   REGULATIONS    ON   ACCOUNT   OF    CHOLERA,    FOREIGN   AND 

INSULAR. 

24.  At  ports  where  cholera  prevails,  special  care  should  be 
taken  to  prevent  the  water  and  the  food  supply  from  being  in- 
fected. The  drinking  water,  unless  of  known  purity,  should  be 
boiled,  and  the  food  thoroughly  cooked  and  protected  against 
contamination  by  ffies,  etc. 

25.  The  latrines  of  vessels  must  be  so  arranged  that  they, 
including  their  discharge  pipes,  can  be  made  and  kept  mechan- 
ically clean. 

26.  Unless  unavoidable,  vessels  should  not  take  water  ballast 
from  a  source  contaminated  or  suspected  of  contamination  by 
cholera.  When  unavoidable^,  the  facts  will  be  noted  on  the  bill 
of  health.     (See  paragraphs  75  and  loi.) 

27.  Certain  food  products,  viz.,  unsalted  meats,  sausages, 
dressed  poultry,  fresh  butter,  fresh  mUk  (unsterilized) ,  fresh 
cheese,  coming  from  cholera-infected  localities  or  through  such 
localities,  if  exposed  to  infection  therein,  should  not  be  shipped. 
Fresh  fruits  and  vegetables,  from  districts  where  cholera  prevails, 
shall  be  shipped  only  under  such  sanitary  supervision  as  viill 
enable  the  inspector  to  certify  that  they  have  not  been  exposed 
to  infection. 

28.  All  rags  and  textile  fabrics  used  in  the  manufacture  of  paper 
and  for  other  purposes  which  are  collected,  packed,  or  handled  in 
any  foreign  port  or  place,  with  the  exceptions  as  hereinafter  speci- 
fied, shall,  prior  to  shipment  to  the  United  States,  be  subjected 


48o 


QUARANTINE. 


INSPECTION  CARD. 

[Immigrants  and  steerage  passengers.] 

Port  of  departure. Date  of  departure .. 

Name  of  ship. _ 

Name  of  immigrant- - Last  permanent  residence.... 


Inspected  and  passed  at 


[Seal  or  stamp  of  consular  or 
medical  officer.] 


Passed  at  quarantine,  port  of 
,  United  States. 


[Date.] 


Passed    by     Immigration 
Bureau,  port  of- 


[Date.] 


[The  following  to  be  filled  in  by  ship's  surgeon  or  agent  prior  to  or  after  embarkation.] 
Shif  s  list  or  manifest. No.  on  ship's  list  or  majiifest 


Berth  No. 


-"*•     IT)    ^       t«^    00       0\ 


.^  J3  .K"  £  -g  0)  (. 

M        M       H  H        M  P.^     '^     " 


VACQNATED. 

[Signature  or  Stamp.] 
[Reverse  Side.] 

Keep  this  Card  to  avoid  detention  at  Quarantine  and  on  Railroads  in  the 
United  States. 

Diese  Karte  muss  aufbevirahrt  werden,  um  Aufenthalt  an  der  Quarantine, 
sowie  auf  den  Eisenbahnen  der  Vereinigt^n  Staaten  zu  vermeiden. 


Cette  carte  doit  etre  conservee  pour  eviter  une  detention  ^  la  Quaran- 
taine,  ainsi  que  sur  les  chemins  de  fer  des  Etats-Unis. 


Deze  kaart  moet  bewaard  vi'orden,  ten  einde  oponthoud  aan  de  Quaran- 
tijn,  alsook  op  de  ijzeren  wegen  der  Vereenigde  Staten  te  vermijden. 


Conservate  questo  biglietto  onde   evitare  detenzione  alia  Quarantina  e 
suUe  Ferrovie  degli  Stati  Uniti. 

Tento  listek  musite  uschovati,  nechcete-li  ukaranteny  (zastaveni  ohlednS 
zjisteni  zdravi)  neb  na  draze  ve  spojenych  statech  zdrzeni  byti. 


Tuto  kartocku  treba  trimat'  u  sebe  aby  sa  predeSlo  zderzovanu  v  karan- 
tene  aj  na  zeleznici  ve  Spojenych  Statoch. 


QUARANTINE  LA  WS  OF  THE  UNITED  STATES.    481 

to  disinfection  by  one  of  the  prescribed  methods.  (Jute  bags  or 
bagging  used  in  baling  cotton,  old  rope,  new  cotton,  or  linen 
cuttings  from  factories  not  included.)  The  disinfection  of  the 
articles  mentioned  above  shall  be  performed  under  the  supervision 
of  a  United  States  consul  or  a  medical  of&cer  of  the  United 
States,  and  a  certificate  in  duplicate,  signed  by  said  consul  or 
medical  officer,  shall  be  issued  with  each  consignment  of  same, 
which  certificate  shall  identify  the  articles  and  state  that  they 
have  been  disinfected  in  accordance  with  the  United  States 
quarantine  regulations.  The  original  certificate  of  disinfection 
shall  be  attached  to  the  consignee's  invoice,  and  where  the 
articles  are  carried  by  sea  the  duplicate  certificate  of  disinfection 
shall  be  attached  to  the  bill  of  health  issued  to  the  vessel  con- 
veying the  same. 

Exceptions. — Such  articles  shipped  from  the  Dominion  of 
Canada  directly  to  the  United  States  shall  be  exempt  from  this 
requirement  if  accompanied  by  affidavits  demonstrating  to  the 
satisfaction  of  the  collector  of  customs  at  the  port  of  arrival 
that  they  have  actually  originated  in  Canada  and  have  not  been 
shipped  from  a  foreign  country  to  Canada,  and  thence  shipped 
to  the  United  States;  and  further,  that  the  port  or  place  where 
collected  or  handled  has  been  free  from  quarantinable  disease 
for  thirty  days  prior  to  shipment. 

29.  Steerage  passengers  and  crew  coming  from  cholera-infected 
districts  should  be  detained  five  days  in  suitable  houses  or  bar- 
racks located  where  there  is  no  danger  from  infection,  and  all 
baggage  disinfected. 

30.  Steerage  passengers  and  crew  from  districts  not  infected 
with  cholera,  shipping  at  a  port  infected  with  cholera,  unless 
passed  through  without  danger  of  infection  and  no  communica- 
tion allowed  between  such  persons  and  the  infected  locality, 
should  be  treated  as  those  in  the  last  paragraph. 

31.  Cabin  passengers  coming  from  cholera-infected  districts 
embarking  at  a  clean  or  an  infected  port  should  produce  satis- 
factory evidence  as  to  their  exact  places  of  abode  during  the  five 
days  immediately  preceding  embarkation.  And  if  it  appears  that 
they  or  their  baggage  have  been  exposed  to  infection,  the  baggage 
should  be  disinfected  and  the  passengers  detained  under  medical 
supervision  a  sufficient  time  to  cover  the  period  of  incubation 
since  last  exposure. 

32.  Should  cholera  appear  in  the  barracks  or  houses  in  which 
passengers  are  undergoing  detention,  no  passenger  from  said 
houses  or  barracks  who  has  been  presumably  exposed  to  this 
new  infection  should  embark  until  after  the  expiration  of  the 
period  of  incubation  of  the  disease  in  question  subsequent  to  the 
last  exposure  to  infection  and  the  application  of  all  necessary 
sanitary  measures. 

31 


482  QUARANTINE. 

SPECIAL  REGULATIONS  ON  ACCOUNT  OF  YELLOW  FEVER,  FOREIGN 
AND   INSULAR. 

33.  It  is  advisable  that  at  ports  where  yellow  fever  prevails, 
precautions  should  be  taken  to  prevent  the  introduction  of 
mosquitoes  (stegomyia)  on  board  the  vessel.  Water  tanks, 
water  buckets,  and  other  collections  of  water  about  the  vessel 
should  be  guarded  in  such  a  manner  that  they  shall  not  become 
breeding  places  for  mosquitoes.  Where  the  vessel  has  lain  in 
such  proximity  to  the  shore  at  such  places  as  to  render  it  liable, 
in  the  opinion  of  the  inspecting  officer,  to  the  access  of  mos- 
quitoes, measures  should  be  taken  to  destroy  mosquitoes  that  may 
have  come  on  board. 

34.  Passengers  and  crew  who,  in  the  opinion  of  the  inspecting 
officer,  have  been  definitely  exposed  to  the  infection  of  yellow 
fever  ii.  e.,  as  from  a  house  or  locality  known  to  be  infected), 
should  not  be  allowed  to  embark  for  six  days  after  said  ex- 
posure. Those  immune  to  yellow  fever  are  exempt  from  this 
provision. 

SPECIAL    REGULATIONS    ON    ACCOUNT    OF    PLAGUE,    FOREIGN    AND 

INSULAR. 

35.  At  ports  or  places  where  plague  prevails  in  men  or  rodents 
every  precaution  should  be  taken  to  prevent  rats,  fleas,  or  other 
vermin  from  getting  aboard.  At  such  ports  or  places  the  vessel 
should  not  lie  at  a  dock  or  tie  to  the  shore  or  anchor  at  any  place 
where  rats  may  gain  access  to  the  vessels.  Lighters  should  not 
harbor  rats,  and  the  introduction  of  rats  from  them  should  be 
very  carefully  guarded  against. 

36.  In  case  lines  are  led  to  the  shore  they  should  be  freshly 
tarred  and  provided  with  inverted  cones  or  such  other  devices  as 
may  prevent  rats  passing  to  the  ship. 

37.  If  the  vessel  docks  the  lines  should  be  treated  as  directed 
in  the  last  paragraph,  and  all  parts  of  the  vessel  fumigated,  simul- 
taneously, if  possible,  for  the  purpose  of  killing  rats  and  other 
vermin,  before  sailing. 

38.  Vessels  arriving  at  a  foreign  port  in  transit,  having  pre- 
viously lain  in  a  plague-infected  port  without  taking  proper  pre- 
cautions to  prevent  the  ingress  of  rats  and  fleas,  should  be  fumi- 
gated to  kill  such  vermin,  provided  effective  fumigation  for  killing 
such  vermin  has  not  already  been  done,  and  that  this  fumigation 
can  be  done  efficiently. 

39.  Articles  which  harbor  or  are  liable  to  harbor  rats  or  rat 
fleas,  should  not  be  shipped  until  freed  of  such  vermin,  either 
by  the  use  of  chemicals,  fumigation,  or  solutions,  or  by  prevent- 
ing the  access  of  rats  for  fifteen  days  before  shipment.  The 
nature  of  the  merchandise  and  the  place  and  method  of  stowing 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.    483 

prior  to  shipment  must  be  considered  in  determining  its  liability 
to  be  a  rat  or  vermin  carrier,  thus:  Bundles  of  hides,  bags  of 
grain,  etc.,  so  stowed  as  to  be  used  as  nesting  places  for  rats 
would  be  flea,  and  might  be  rat,  carriers. 

When  the  cargo  of  a  vessel  consists  of  grain  or  other  rat  food, 
extra  precautions  should  be  taken  to  prevent  rats  from  going 
aboard. 

Hides  chemically  cured  are  not  liable  to  harbor  rats  or  rat 
fleas;  and  loose,  single  hides  are  less  liable  to  do  so  than  when 
baled. 

40.  Passengers  and  crew  who,  in  the  opinion  of  the  inspecting 
ofl&cer,  have  been  definitely  exposed  to  the  infection  of  plague 
(i.  e.,  as  from  a  house  or  locality  known  to  be  infected)  should 
not  be  allowed  to  embark  for  seven  days  after  said  exposure, 
unless  already  immune  to  plague  by  recent  previous  attack,  or 
prophylactic  serum.  All  baggage  from  such  ports  shall  be  sub- 
ject to  inspection,  and  if  necessary  disinfected  and  treated  to 
destroy  vermin. 

SPECIAL  REGULATIONS  ON  ACCOUNT  OF   SMALL-POX,  FOREIGN  AND 

INSULAR. 

41.  Steerage  passengers  and  crew  coming  from  districts  where 
small-pox  prevails  in  epidemic  form,  or  who  have  been  exposed  to 
small-pox,  should  be  vaccinated  before  embarkation,  unless  they 
show  satisfactory  evidence  of  having  acquired  immunity  to 
small-pox  by  previous  attack,  or  successful  vaccination  within 
one  year,  and  their  baggage  inspected  and  if  necessary  disin- 
fected. 

SPECIAL   REGULATIONS   ON  ACCOUNT   OF  TYPHUS   FEVER,   FOREIGN 

AND   INSULAR. 

42.  Steerage  passengers  and  crew  who,  in  the  opinion  of  the 
inspection  officer,  have  been  exposed  to  the  infection  of  typhus 
fever,  should  not  be  allowed  to  embark  for  a  period  of  at  least 
twelve  days  after  such  exposure  and  until  their  baggage  has  been 
disinfected  and  the  destruction  of  vermin  assured. 

SPECIAL   REGULATIONS    ON    ACCOUNT    OF    LEPROSY,    FOREIGN   ANT) 

INSULAR. 

43.  No  alien  who  is  a  leper  should  be  allowed  to  embark  for  the 
United  States. 

RECORDS,  REPORTS,  ETC.,  FOREIGN  AND  INSULAR. 

44.  The  officer  making  the  inspection  will  preserve  in  his 
office  a  record  of  each  inspection  made  and  of  each  immunity 


484  QUARANTINE. 

certificate  given;  a  copy  of  each  certificate  of  disinfection  and 
of  each  bill  of  health  issued. 

A  weekly  report  of  the  transactions  of  his  ofl5.ce  shall  be  for- 
warded to  the  Surgeon-General  at  Washington,  D.  C. 

45.  In  addition  to  the  duties  prescribed,  the  medical  officer 
when  detailed  in  accordance  with  the  act  of  Congress  approved 
February  15,  1893,  shall  furnish  such  reports  to  the  Surgeon- 
General  of  the  Public  Health  and  Marine-Hospital  Service  as  he 
may  be  able  to  make  upon  sanitary  conditions  and  other  matters 
affecting  the  public  health  and  the  welfare  of  the  Service  admin- 
istration. 

REQUIREMENTS   AT   SEA.^ 

46.  The  master  of  a  vessel  should  observe  the  following  meas- 
ures on  board  his  vessel : 

{a)  The  water-closets,  forecastle,  bilges,  and  similar  portions 
of  the  vessel  liable  to  harbor  infection  should  be  disinfected  and 
frequently  cleansed. 

Q})  Free  ventilation  and  rigorous  cleanliness  should  be  main- 
tained in  all  portions  of  the  ship  during  the  voyage  and  measures 
taken  to  destroy  rats,  mice,  fleas,  flies,  roaches,  mosquitoes,  and 
other  vermin. 

(c)  A  patient  sick  of  a  communicable  disease  should  be  isolated 
and  one  member  of  the  crew  detailed  for  his  care  and  comfort, 
who,  if  practicable,  should  be  immune  to  the  disease. 

id)  Communication  between  the  patient  or  his  nurse  and  other 
persons  on  board  should  be  reduced  to  a  minimum. 

(e)  Used  clothing,  body  linen,  and  bedding  of  the  patient  and 
nurse  should  be  immersed  at  once  in  boiling  water  or  in  a  disin- 
fecting solution. 

(/)  The  compartment  from  which  the  patient  was  removed 
should  be  disinfected  and  thoroughly  cleansed.  Articles  liable  to 
convey  infection  should  remain  in  the  compartments  during  the 
disinfection  when  gaseous  disinfection  is  used. 

(g)  Any  person  suffering  from  malaria  or  y'eUow  fever  should 
be  kept  under  mosquito  bars  and  the  apartment  in  which  he  is 
confined  closely  screened  with  mosquito  netting.  All  mosquitoes 
on  board  should  be  destroyed  by  burning  pyrethrum  powder 
(Persian  insect  powder)  or  by  fumigation  with  sulphur.  Mos- 
quito larvae  (wigglers  or  wiggle-tails)  should  be  destroyed  in 
water-barrels,  casks,  and  other  collections  of  water  about  the 
vessel  by  the  use  of  petroleum  (kerosene) ;  where  this  is  not  prac- 
ticable, use  mosquito  netting  to  prevent  the  exit  of  mosquitoes 
from  such  breeding  places. 

1  These  requirements  at  sea  are  largely  advisory  in  character,  but  it  is  never- 
theless true  that  a  careful  compliance  with  them  should  tend,  at  the  port  of 
arrival,  to  largely  relieve  the  stringency  of  quarantine  measures. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  485 

(//)  In  the  case  of  plague,  special  measures  must  be  taken  to 
destroy  rats,  mice,  fleas,  ants,  and  other  vermin  on  board. 

(/)  In  the  case  of  t}-phus^  special  measures  should  be  taken  in 
addition  to  disinfection  to  destroy  vermin. 

(/')  In  the  case  of  cholera,  tx-phoid  fever,  or  dysentery,  the 
drinking  water  should  be  boiled  and  the  food  thoroughly  cooked. 
The  discharges  from  the  patient  should  be  immediately  disin- 
fected and  thrown  overboard. 

47.  An  inspection  of  the  vessel,  including  the  steerage,  should 
be  made  by  the  ship's  physician  once  each  day. 

48.  Should  cholera,  yellow  fever,  small-pox,  t^^hus  fever, 
plague,  or  any  other  commimicable  disease  appear  on  board  a 
ship  while  at  sea,  those  who  show  symptoms  of  these  diseases 
should  be  immediately  isolated  m  a  proper  place;  the  ship's 
physician  should  then  immediately  notify  the  captain,  who  should 
note  same  in  his  log,  and  all  of  the  effects  liable  to  convey  infec- 
tion which  have  been  exposed  to  infection  should  be  destroyed  or 
disinfected. 

49.  The  hospital  should  be  disinfected  as  soon  as  it  becomes 
vacant. 

50.  The  dead  should  be  enveloped  in  a  sheet  saturated  with 
one  of  the  strong  disinfecting  solutions,  without  previous  washing 
of  the  body,  and  at  once  buried  at  sea  or  placed  in  a  coffin  her- 
metically sealed. 

51.  A  complete  clinical  record  should  be  kept  by  the  ship's 
surgeon  of  all  cases  of  sickness  on  board,  and  the  record  deliv- 
ered to  the  quarantine  officer  at  the  port  of  arrival. 

52.  The  follo'vv'ing  disinfecting  solutions  are  recommended  for 
use  at  sea: 

FORiTCXAS   FOR   STRONG  DlSESTFECTING   SOLUTIONS. 

Bichlorid  of  Mercury  (i  :  500). 

Bichlorid  of  mercury i  part 

Sea-water roo  parts. 

Carbolic  Acid  (5  per  cent.). 

Alcohol 50  parts 

Carbolic  acid,  pvire 50  parts 

Then  add  fresh  water 900  parts. 

Foiiirui.AS  FOR  We.\k  Solutions. 
Bichlorid  of  Mercury  (i  :  1000). 

Eichlorid  of  mercury i  part 

Sea-water 1000  parts. 

1  It  is  now  accepted  that  tj^phus  fever  may  be  transmitted  through  the 
agency  of  lice. 


486  QUARANTINE. 

Carbolic  Acid  (25  per  cent.). 

Carbolic  acid,  piire 25  parts 

Fresh  water 1000  parts. 

Formalin  (5  per  cent.). 

Formalin  (or  formol) 25  parts 

Water 950  parts. 

It  is  suggested  that  a  vessel  should  carry  for  every  100  passen- 
gers: Bichlorid  of  mercury,  5  pounds;  carbolic  acid,  10  pounds; 
alcohol,  10  pounds,  and  formalin,  10  pounds. 

DOMESTIC   REGULATIONS. 

Quaxantine  Regulations  to  be  Observed  at  Ports  and  on  the  Frontiers  of 
the  United  States  and  its  Possessions  and  Dependencies. 

Preamble. 

\_j 

53.  At  or  convenient  to  the  principal  ports,  quarantine  stations 
should  be  equipped  with  all  appliances  for  the  inspection  and 
treatment  of  vessels,  their  passengers,  crews,  and  cargoes. 

54.  For  all  ports  where  such  provisions  have  not  been  made, 
inspection  stations  should  be  maintained.  An  inspection  service 
should  be  maintained  for  every  port  throughout  the  year. 

55.  At  a  fully  equipped  quarantine  station  there  should  be 
adequate  provision  for  boarding  and  inspection,  apparatus  for 
mechanical  cleansing  of  vessels,  apparatus  for  disinfection  by 
steam,  by  sulphur,  by  formaldehyd,  by  disinfecting  solutions,  or 
any  other  methods  prescribed  in  these  regulations;  also  a  clinical 
laboratory,  hospitals  for  contagious  and  doubtful  cases,  a  steam 
laundry,  detention  barracks  for  suspects,  bathing  facilities,  a  cre- 
matory, a  sufi&cient  supply  of  good  water,  and  a  proper  system 
for  the  disposal  of  sewage. 

56.  The  personnel  of  quarantine  stations  in  the  yellow-fever 
zone  and  on  fruiters  and  other  vessels  of  regular  lines  bound  for 
southern  ports  from  ports  where  yellow  fever  prevails  should  be 
immune  to  yellow  fever. 

57.  At  quarantine  stations  all  articles  liable  to  convey  infection 
should  be  handled  only  by  the  employees  of  said  station  unless 
the  services  of  the  crew  of  the  vessel  in  quarantine  are  indispen- 
sable. 

58.  Vessels  having  been  treated  at  national  quarantine  stations 
that  are  located  a  considerable  distance  from  the  ports  of  entry 
of  said  vessels  may  be  inspected  by  the  local  quarantine  officer, 
and  if  for  any  sanitary  reason  it  is  considered  inadvisable  to  admit 
the  vessel,  he  should'  report  the  facts  immediately  by  telegraph, 
when  possible,  to  the  Surgeon-General  of  the  Public  Health  and 
Marine-Hospital  Service,  detaining  the  vessel  pending  his  action. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   487 

59.  The  following  regulations  are  the  required  minimum 
standard  and  do  not  prevent  the  addition  of  such  other  rules  as, 
for  special  reasons,  may  be  legally  made  by  State  or  local  authori- 
ties. 

INSPECTION. 

60.  Every  vessel  subject  to  quarantine  inspection,  entering  a 
port  of  the  United  States,  its  possessions  or  dependencies,  shall 
be  considered  in  quarantine  until  given  free  pratique.  Such  ves- 
sel shall  fly  a  yellow  flag  at  the  foremost  head  from  sunrise  to 
sunset,  and  shall  observe  all  the  other  requirements  of  vessels 
actually  quarantined. 

61.  Vessels  arriving  at  ports  of  the  United  States  under  the 
following  conditions  shall  be  inspected  by  a  quarantine  officer 
prior  to  entry: 

(a)  All  vessels  from  foreign  ports  except  those  enumerated  in 
paragraph  4. 

{b)  Any  vessel  with  sickness  on  board. 

(c)  Vessels  from  domestic  ports  where  cholera,  plague,  or  yel- 
low fever  prevails,  or  where  small-pox  or  tophus  fever  prevails  in 
epidemic  form. 

{d)  Vessels  from  ports  suspected  of  infection  with  yellow  fever, 
having  entered  a  port  north  of  the  southern  boundary  of  Mary- 
land without  disinfection,  shall  be  subjected  to  a  second  inspec- 
tion before  entering  any  ports  south  of  said  latitude  during  the 
quarantine  season  of  such  port. 

62.  The  inspections  of  vessels  required  by  these  regulations 
shall  be  made  between  sunrise  and  sunset,  except  in  case  of 
vessels  in  distress.  Exception  may  also  be  made  in  the  case  of 
fruit  vessels  carrying  perishable  cargoes,  and  regular  line  vessels 
carrying  passengers,  under  regulations  approved  by  the  Secretary 
of  the  Treasury. 

63.  In  making  the  inspection  of  a  vessel,  the  bill  of  health  and 
clinical  record  of  all  cases  treated  during  the  voyage,  crew  and 
passengers'  lists  and  manifests,  and  when  necessary,  the  ship's 
log  shall  be  examined.  The  crew  and  passengers  shall  be  mus- 
tered and  examined  and  compared  with  the  lists  and  manifests 
and  any  discrepancies  investigated.  The  clinical  thermometer 
should  be  used  in  the  examination  of  the  personnel  of  vessels  under 
suspicion.  When  a  freight  manifest  shows  that  rags  and  other 
articles  requiring  disinfection  under  these  regulations  are  carried 
by  the  vessel,  a  certificate  of  disinfection,  signed  by  a  United 
States  consul  or  a  medical  officer  of  the  United  States,  shall  be 
exhibited  and  compared  with  same.  If  no  certificate  of  disinfec- 
tion is  produced,  the  collector  of  customs  at  the  port  of  entry  shall 
be  notified  of  same  by  the  quarantine  officer.  The  collector  of 
customs  shall  then  hold  such  consignment  in  a  designated  place 


488  QUARANTINE. 

separate  from  other  freight  pending  the  arrival  of  the  certificate 
of  disinfection;  and  in  the  event  of  its  non-arrival,  the  articles 
shall  be  disinfected  as  hereinbefore  prescribed,  or  shall  be  re- 
turned by  the  common  carrier  conveying  same. 

64.  The  medical  officers  of  the  United  States,  duly  clothed  with 
authority  to  act  as  quarantine  officers  at  any  port  or  place  within 
the  United  States,  and  when  performing  the  said  duties,  are  here- 
by authorized  to  take  declarations  and  administer  oaths  in 
matters  pertaining  to  the  administration  of  the  quarantine  laws 
and  regulations  of  the  United  States.  (Act  of  March  2,  1901, 
sec.  12.) 

65.  No  person,  except  the  quarantine  officer,  his  employees, 
United  States  customs  officers,  pilots,  or  other  persons  authorized 
by  the  quarantine  officer,  shall  be  permitted  to  board  any  vessel 
subject  to  quarantine  inspection  until  after  the  vessel  has  been 
inspected  by  the  quarantine  officer  and  granted  free  pratique,  and 
all  such  persons  so  boarding  such  vessel  shall,  in  the  discretion  of 
the  quarantine  officer,  be  subject  to  the  same  restrictions  as  the 
personnel  of  the  vessel. 

66.  Towboats  or  any  other  vessels  having  had  communication 
with  vessels  subject  to  inspection  shall  themselves  be  subject  to 
inspection. 

67.  After  arrival  at  a  quarantine  station  of  a  vessel  carrying 
immigrants  and  upon  which  there  has  appeared  during  the  last 
voyage  a  case  of  cholera,  small-pox,  typhus  fever,  or  plague,  and 
after  quarantine  measures  provided  by  regulations  of  the  Treasury 
Department  have  been  enforced  and  the  vessel  given  free  pratique 
it  is  hereby  ordered  that  notification  of  the  above-mentioned 
facts  be  transmitted  by  the  quarantine  officer  to  the  Commis- 
sioner of  Immigration  at  the  port  of  arrival,  who  shall  be  re- 
quested to  transmit,  by  mail  or  telegraph,  to  the  State  health 
authorities  of  the  several  States  to  which  immigrants  from  said 
vessel  are  destined,  the  date  of  departure,  route,  number  of 
immigrants,  and  the  point  of  destination  in  the  respective  States 
of  the  immigrants  from  said  vessel,  together  with  the  statement 
that  said  immigrants  are  from  a  vessel  which  has  been  subject  to 
quarantine  by  reason  of  infectious  disease,  naming  the  disease. 
This  information  is  furnished  to  State  health  officers  for  the 
purpose  of  enabling  them  to  maintain  such  surveillance  over  the 
arriving  immigrants  as  they  may  deem  necessary. 

68.  When  a  vessel  arriving  at  quarantine  has  on  board  any  of 
the  communicable  but  unquarantinable  diseases,  the  quarantine 
officer  shall  promptly  inform  the  local  health  authorities  of  the 
existence  of  such  disease  aboard  and  shall  make  every  effort  to 
furnish  such  notification  in  ample  time,  if  possible,  to  permit  of 
the  case  being  seen  by  the  local  authorities  before  discharge  from 
the  vessel. 


QUARANTINE  LA  WS  OF  THE  UNITED  STA  TES.  489 


QUARANTINE. 

6g.  Vessels  arriving  under  the  following  conditions  shall  be 
placed  in  quarantine: 

(a)  With  quarantinable  disease  on  board  or  having  had  such 
disease  on  board  during  the  voyage. 

{b)  Any  vessel  which  the  quarantine  officer  considers  in- 
fected. 

(c)  A  vessel  arriving  at  a  port  south  of  the  southern  boundary 
of  Virginia  in  the  season  of  close  quarantine.  April  i  to  November 
I,  from  a  tropical  American  port,  unless  said  port  is  known  to  be 
free  from  yellow  fever. 

{d)  Vessels  arriving  at  ports  north  of  this  line,  and  south  of 
the  southern  boundary  of  Maryland,  between  May  15  and 
October  i,  if  from  a  tropical  port,  unless  said  port  is  known  to  be 
free  from  yellow  fever. 

(e)  Vessels  arriving  at  a  southern  port,  referred  to  in  para- 
graphs (c)  and  {d)  during  the  season  of  close  quarantine  for  such 
ports,  via  a  northern  port,  when  from  a  port  known  to  be  infected 
with  yellow  fever,  unless  six  days  have  elapsed  since  the  fumi- 
gation of  the  vessel  in  such  northern  port  and  certificate  be  pre- 
sented from  the  quarantine  officer  at  such  northern  port,  or  an 
accredited  medical  officer  of  the  United  States. 

(/)  In  the  case  of  vessels  arriving  at  a  northern  port  without 
sickness  on  board  from  ports  where  yellow  fever  prevails,  the  per- 
sonnel shall  be  detained  under  observation  at  quarantine  to  com- 
plete five  days  from  the  port  of  departure. 

{g)  Towboats  and  other  vessels  having  had  communication 
with  vessels  subject  to  quarantine  shall  themselves  be  quaran- 
tined if  they  have  been  exposed  to  infection. 

70.  Vessels  engaged  in  the  fruit  trade  may  be  admitted  to 
entry  without  detention,  provided  that  they  have  complied  in  all 
respects  with  the  special  rules  and  regulations  made  by  the 
Secretary  of  the  Treasury  with  regard  to  vessels  engaged  in  said 
trade. 

GENERAL  REQUIREMENTS   AT   QUARANTINE. 

71.  Pilots  will  be  detained  in  quarantine  a  sufficient  time  to 
cover  the  period  of  incubation  of  the  disease  for  which  the  vessel 
is  quarantined,  if,  in  the  opinion  of  the  quarantine  officer,  such 
pilots  have  been  exposed  to  infection.  The  dunnage  of  pilots 
shall  be  disinfected  when  necessary. 

72.  No  direct  communication  shall  be  allowed  between  any 
vessel  in  quarantine  and  any  person  or  place  outside,  and  no  com- 
munication whatever  between  quarantine  or  any  vessel  in  quaran- 
tine and  any  person  or  place  outside  except  under  the  supervision 
of  the  quarantine  officer. 


490  QUARANTINE. 

73.  Street  cleanings,  street  sweepings,  or  any  other  form  of 
ballast  containing  organic  refuse  must  be  discharged  at  the  quar- 
antine station. 

74.  No  presumably  infected  ballast  shall  be  allowed  to  leave 
the  quarantine  station  until  disinfected. 

75.  After  a  vessel  has  been  rendered  free  from  infection,  it  may 
be  furnished  with  a  fresh  crew  and  released  from  quarantine, 
while  all  or  part  of  the  personnel  is  detained.  Under  these  cir- 
cumstances the  quarantine  officer  must  exercise  the  greatest  care 
that  the  vessel  shall  not  become  reinfected,  especially  by  contact 
with  persons  in  quarantine  or  infected  objects. 

76.  Vessels  detained  at  any  national  quarantine  will  be  subject 
to  such  additional  rules  and  regulations  as  may  be  promulgated 
from  time  to  time  by  the  Surgeon-general. 

77.  The  form  of  certificate  which  shall  be  issued  to  a  vessel  by 
the  health  officer  when  he  releases  her  from  quarantine  shall  be 
prescribed  by  the  Surgeon-General  of  the  Public  Health  and 
Marine-Hospital  Service,  and  shall  embody  the  statement  that 
the  vessel  has  in  all  respects  complied  with  the  quarantine 
regulations  prescribed  by  the  Secretary  of  the  Treasury,  and 
that  in  the  opinion  of  the  quarantine  officer  she  will  not  convey 
quarantinable  disease,  and  that  said  vessel  is  granted  free  pratique 
to  enter  her  port  of  destination,  the  name  of  which  is  to  be  em- 
bodied in  the  blank. 

78.  The  persons  detained  shall  be  inspected  by  the  physician 
twice  daily,  and  be  under  his  constant  surveillance,  and  no  inter- 
course will  be  allowed  between  different  groups  while  in  quaran- 
tine. 

79.  No  articles  from  an  infected  vessel  shall  be  carried  into  the 
place  of  detention  until  disinfected. 

80.  Cleanliness  of  quarters  and  of  person  shall  be  enjoined  and 
daily  enforced.  Disinfection  shall  be  practised  where  there  is 
any  possibility  of  infection. 

81.  Water-closets,  urinals,  privies,  or  troughs  shall  be  pro- 
vided. 

82.  In  any  group  in  which  communicable  disease  appears,  the 
sick  will  be  immediately  isolated  in  hospital,  and  the  remaining 
persons  in  the  group  and  their  effects  appropriately  treated  and 
then  removed  to  other  quarters,  if  possible,  and  the  compartments 
disinfected. 

83.  Communication  between  the  physician  and  attendants  of 
the  hospital  and  those  detained  in  other  parts  of  the  quarantine 
station  shall  be  reduced  to  a  minimum. 

84.  No  convalescent  shall  be  discharged  from  quarantine  until 
after  a  sufficient  time  has  elapsed  to  insure  his  freedom  from 
infection,  and  this  is  to  be  determined  by  bacteriologic  examina- 
tion where  possible. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   491 

85.  No  other  person  shall  be  discharged  from  quarantine  until 
the  period  of  incubation  of  the  disease  has  elapsed  since  the  last 
exposure  to  infection. 

86.  The  body  of  no  person  dead  of  quarantinable  disease  shall 
be  allowed  to  pass  through  quarantine  until  one  year  has  elapsed 
since  death.  Such  bodies  must  be  transported  in  hermetically 
sealed  coffins,  the  outsides  of  which  have  been  carefully  disin- 
fected. 

In  the  case  of  the  bodies  of  such  persons  as  may  have  died  on 
the  voyage  or  upon  arrival  at  quarantine,  cremation  should  be 
resorted  to  if  practicable  and  consented  to;  if  not,  the  body 
should  be  wrapped  without  preliminary  washing  in  a  sheet  satu- 
rated with  a  solution  of  bichlorid  of  mercury  i :  500  and  buried, 
surrounded  by  caustic  lime. 

87.  The  quarantine  ofi&cer  shall  report  to  the  Secretary  of  the 
Treasury  all  violations  of  the  quarantine  laws.  He  should  also 
report  the  facts  in  the  case  to  the  Surgeon-General  of  the  Public 
Health  and  Marine-Hospital  Service. 

88.  The  quarantine  officer  shall  report  to  the  collector  of  cus- 
toms any  vessel  which  arrives  without  the  bill  of  health  herein- 
before prescribed. 

89.  AH  vessels  requiring  inspection  under  these  regulations 
must  present  to  the  collector  of  customs  at  the  port  of  entry  the 
quarantine  certificate  above  prescribed. 

SPECIAL  REGULATIONS  ON  ACCOUNT  OF  CHOLERA. 

90.  For  the  purpose  of  these  regulations  five  days  shall  be  con- 
sidered as  the  period  of  incubation  of  cholera. 

91.  If  the  vessel  carry  persons  from  cholera-infected  ports  or 
places,  a  bacteriologic  examination  should  be  made  of  any  cases 
of  diarrhea  to  exclude  cholera  before  granting  free  pratique. 

92.  If  cholera  has  appeared  on  board,  remove  all  passengers 
from  the  vessel  and  all  of  the  crew,  save  those  necessary  to  care 
for  her;  place  the  sick  in  hospital.  Carefully  isolate  those  espe- 
cially suspected,  and  segregate  the  remainder  in  small  groups. 
No  communication  should  be  held  between  these  groups.  Those 
believed  to  be  especially  capable  of  conveying  infection  must  not 
enter  the  place  of  detention  until  they  are  bathed  and  furnished 
with  non-infected  clothing ;  nor  shall  any  material  capable  of  con- 
veying infection  be  taken  into  the  place  of  detention,  especially 
food  and  water. 

93.  Water  and  food  supply  must  be  strictly  guarded  to  prevent 
contamination,  and  issued  to  each  group  separately. 

94.  Food  of  a  simple  character,  sufficient  in  quantity,  thor- 
oughly cooked,  shall  be  issued  to  those  detained  in  quarantine. 
No  fruit  or  uncooked  vegetables  shall  be  permitted. 


492  QUARANTINE. 

95.  The  greatest  care  must  be  exercised  to  prevent  the  spread 
of  the  infection  through  the  agency  of  flies  or  other  insects. 

96.  The  dejecta  from  all  persons  in  quarantine  on  account  of 
cholera  shall  be  disinfected  before  final  disposition. 

97.  The  water  supply  of  the  vessel,  if  suspected  of  infection, 
must  be  disinfected  and  then  changed  without  delay;  the  casks 
or  tanks  disinfected,  and  after  thorough  rinsing  refilled  from  a 
source  of  undoubted  purity,  or  the  water  furnished  must  have 
been  recently  boiled. 

98.  The  baggage  or  effects  of  passengers  and  crew  that  may 
have  been  exposed  to  infection  must  be  disinfected. 

99.  Articles  of  cargo  which  have  been  exposed  to  infection  and 
are  liable  to  convey  the  same  must  be  disinfected. 

100.  Living  apartments  and  their  contents  and  such  other  por- 
tions of  the  vessel  as  have  been  exposed  to  infection  must  be 
disinfected. 

loi.  Water  ballast  taken  on  at  a  cholera-infected  port  should 
be  discharged  at  sea,  or  if  discharged  in  fresh  or  brackish  water, 
must  previously  be  disinfected.  Vessels  arriving  with  water  bal- 
last presumably  infected  must  return  to  sea  under  guard  in  order 
to  discharge  such  ballast.  If  practicable,  the  tanks  should  be  dis- 
infected before  being  flushed,  and  refilled  with  sea-water.  (See 
also  paragraphs  26  and  75.) 

SPECIAL  REGULATIONS   ON  ACCOUNT   OF   YELLOW  EEVER. 

102.  For  the  purpose  of  these  regulations,  six  days  shall  be 
considered  as  the  period  of  incubation  of  yellow  fever. 

103.  A  vessel  aboard  which  a  case  of  yellow  fever  has  oc- 
curred at  any  time  during  the  voyage  shall  be  treated  as  fol- 
lows: 

(a)  Careful  visual  and  thermometer  inspection  of  all  persons. 

(6)  The  sick  are  to  be  immediately  disembarked,  protected  by 
netting  against  the  access  of  stegomyia  mosquitoes,  and  trans- 
ferred to  a  place  of  isolation. 

(c)  Other  persons  should  be  disembarked,  if  possible,  and  sub- 
jected to  an  observation  of  six  days,  dating  from  the  day  of  last 
possible  exposure. 

{d)  Persons  under  observation  presenting  an  elevation  of  tem- 
perature above  37.6°  C.  shall  be  isolated  in  a  screened  apart- 
ment. 

(e)  The  ship  shall  be  moored  at  least  200  meters  from  the 
inhabited  shore. ^ 

(/)  The  ship  shall  be  fumigated  for  the  destruction  of  mos- 
quitoes before  the  discharge  of  cargo,  if  possible.  If  a  fumiga- 
tion be  not  possible  before  the  discharge  of  the  cargo,  the  dis- 

1  No  national  quarantine  station  is  within  200  meters  of  an  inhabited  shore. 


QUARANTINE  LA  WS  OF  THE  UNITED  STA  TES.  493 

charge  of  cargo  shall  be  under  the  supervision  of  the  quarantine 
ofl&cer,  and  may  be  permitted  as  follows:  By  (i)  the  employ- 
ment of  immune  persons  for  discharging  the  cargo;  or  (2)  if 
non-immunes  be  employed,  they  shall  be  kept  under  observation 
during  the  discharging  of  cargo  and  for  six  days,  to  date  from 
the  last  day  of  exposure  on  board. 

104.  A  vessel  which  has  lain  in  such  proximity  to  the  shore  of  a 
port  infected  or  suspected  as  to  render  it  "liable  to  the  access  of 
stegomyia  mosquitoes  is  to  be  subjected  to  the  measures  which 
are  indicated  in  (a),  (c),  and  (/)  of  the  preceding  paragraph. 

105.  A  vessel  arriving  at  a  southern  port  which,  although  com- 
ing from  an  infected  or  suspected  port,  has  had  neither  death  nor 
case  of  yellow  fever  on  board,  either  before  departure,  during 
the  voyage,  or  at  the  time  of  arrival,  and  which  the  quarantine 
officer  is  satisfied  has  not  lain  in  such  proximity  to  the  shore  as 
to  render  it  liable  to  the  access  of  stegomyia  mosquitoes,  or 
which  has  been  fumigated  under  the  supervision  of  an  accredited 
medical  officer  of  the  United  States  immediately  before  sailing, 
may,  upon  arrival  at  a  port  of  destination  in  the  United  States 
with  good  sanitarv^  history  and  in  good  condition,  be  subjected 
to  the  following  treatment: 

(o)  If  arriving  in  six  days  or  less,  she  may  be  admitted  to 
pratique,  with  or  without  fumigation,  in  the  discretion  of  the 
quarantine  officer,  and  without  further  detention  than  is  neces- 
sary to  complete  six  days. 

{h)  If  arriving  after  six  days  and  within  twelve  days,  she  may 
be  immediately  fumigated  and  admitted  without  detention. 

(c)  If  arriving  after  a  longer  voyage  than  twelve  days,  she  shall 
be  treated  as  required  by  paragraph  103  (a),  (c),  and  (/).^  If  the 
vessel  should  have  been  in  transit  for  a  considerable  number  of 
days  it  is  obvious  that  a  case  of  yellow  fever  may  have  occurred 
and  recovered,  leaving  the  vessel  infected  and  not  affording  any 
opportunity  to  the  quarantine  officer  to  determine  same. 

106.  Traffic  without  detention  may  be  allowed  during  the 
close  quarantine  season,  from  ports  infected  or  suspected  of 
infection  with  yellow  fever  to  ports  in  the  United  States  south  of 

1  A  vessel  in  this  class  is  one  aboard  which  there  are  no  infected  stegomjaae 
and  no  persons  infective  to  stegomyife — that  is,  sick  of  yellow  fever. 

It  may  have  aboard  uninfected  stegomyiae,  which  bred  aboard  or  were 
carried  aboard  from  some  previous  port,  and  persons  in  the  incubative  period 
of  yellow  fever. 

If  a  case  of  yellow  fever  develops  and  infects  the  stegomyiae  aboard,  the 
stegomyice  must  be  destroyed  before  granting  pratique,  but  as  such  stegomyiae 
hav^e  not  been  found  capable  of  conveying  yellow  fever  imtil  twelve  days 
have  elapsed  after  biting  one  sick  of  yellow  fever,  the  personnel  of  the  vessel 
is  not  exposed  to  infection  up  to  this  time  and  can  be  landed  -with  safety  prior 
to  this  time.  Twelve  days  is  the  minimum  time  observed,  one  case  only,  for 
the  incubation  in  the  mosquito — the  extrinsic  incubation  of  yellow  fever. 


494  QUARANTINE. 

the  southern  boundary  of  Maryland  under  the  following  con- 
ditions : 

(c)  The  vessel  must  lie  at  approved  moorings  in  the  open  har- 
bor; the  crew  must  not  be  allowed  ashore  at  the  port  of  depart- 
ure. Every  possible  precaution  must  be  taken  to  prevent  the 
ingress  of  stegomyia  mosquitoes  and  their  access  to  the  crew. 

(6)  All  passengers  and  the  officer  who  must  go  ashore  to  enter 
his  vessel  must  be  immune  to  yellow  fever,  or  must  have  been 
free  from  possible  exposure  to  yellow  fever  for  six  days  imme- 
diately prior  to  embarking. 

(c)  All  the  above  conditions  to  be  certified  to  specifically  by  an 
accredited  medical  officer  of  the  United  States. 

107.  All  persons  who  can  prove  their  immunity  to  yellow  fever, 
to  the  satisfaction  of  the  health  authorities,  or  who  have  not  been 
exposed  to  possible  infection  of  yellow  fever,  may  be  permitted  to 
land  at  once.^ 

108.  For  the  destruction  of  mosquitoes  there  shall  be  a  com- 
plete and  simultaneous  fumigation  of  all  parts  of  the  vessel  by 
sulphur  dioxid  gas,  2  per  cent,  volume  gas,  two  hours'  exposure. 
Where  sulphur  is  liable  to  injure  articles,  pyrethrum  powder, 
camphophenol,  or  other  approved  culicide  may  be  used  instead. 
(See  also  paragraph  67.) 

SPECIAL  REGULATIONS   ON   ACCOUNT   OF   PLAGUE. 

109.  For  the  purpose  of  these  regulations  seven  days  shall  be 
considered  as  the  period  of  incubation  of  plague. 

no.  Ships  aboard  which  plague  has  occurred  in  men  or  rats 
are  to  be  subjected  to  the  following  treatment: 

(a)  Careful  inspection. 

(5)  The  sick,  if  any,  are  to  be  immediately  disembarked  and 
isolated. 

(c)  The  destruction  of  rats  on  shipboard  shall  be  effected  as 
soon  as  practicable.  Cargo  must  be  partially  or  completely 
removed  if  necessary  for  effective  destruction  of  rats.  Proper 
precautions  shall  be  taken  to  prevent  rats  getting  ashore. 

((/)  All  personnel  to  be  held  under  observation  not  less  than  five 
days,  which  period  may,  in  the  judgment  of  the  quarantine  officer, 
be  extended  to  seven  days  in  special  cases. 

{e)  Soiled  linen,  personal  effects  in  use,  the  belongings  of  crew 
and  passengers  which,  in  the  opinion  of  the  quarantine  officer 
are  considered  as  infected,  shall  be  disinfected  and  rendered 
free  from  vermin. 

(/)  In  all  cases  the  quarantine  officer  shall  assure  himself  that 

1  The  evidence  of  immunity  which  may  be  accepted  by  the  sanitary  inspec- 
tor is:  First,  proof  of  previous  attack  of  yellow  fever;  second,  proof  of  con- 
tinued residence  in  an  endemic  focus  of  yellow  fever  for  ten  years. 


QUARANTINE  LA  WS  OF  THE  UNITED  STA  TES.  495 

the  vessel  is  free  from  rats  and  vermin  before  granting  free 
pratique. 

111.  Vessels  from  ports  infected  with  plague,  in  men  or  rats, 
which  have  docked  or  which  have  not  taken  precautions  neces- 
sary to  prevent  the  ingress  of  rats  or  vermin,  and  on  which 
effective  measures  have  not  been  taken  to  destroy  same  under 
the  supervision  of  an  accredited  medical  officer  of  the  United 
States,  shall,  upon  arrival,  be  treated  as  follows: 

(a)  Careful  inspection. 

(6)  Fumigation  for  the  destruction  of  rats. 

112.  Vessels  engaged  in  trade  from  ports  infected  with  plague 
shall  have  such  measures  taken  as  will  free  them  from  rats  not  less 
than  once  every  six  months.  This  is  best  done  by  fumigation 
when  the  vessel  is  empty. 

113.  Treatment  of  vessels  without  cargo  for  plague  shall  be  the 
simultaneous  fumigation  with  sulphur  dioxid,  not  less  than  2  per 
cent,  gas,  for  six  hours'  exposure. 

114.  Treatment  of  vessels  with  cargo  shall  be  the  fumigation 
with  sulphur  dioxid  4  per  cent,  gas,  six  to  twelve  hours'  exposure, 
according  to  the  stowing. 

115.  Infected  vessels  may  require  partial  or  complete  discharge 
of  cargo  and  fractional  fumigation  for  efficient  deratization. 

116.  For  the  deratization  of  all  vessels,  except  those  which 
have  had  plague  in  men  or  rats  during  the  voyage,  the  oxids  of 
carbon,  applied  by  special  apparatus  in  the  volume  and  with  the 
exposure  described  in  paragraph  185,  may  be  used.  (See  also 
paragraph  67.) 

SPECIAL   REGULATIONS   ON   ACCOUNT   OF   SMALL-POX. 

117.  For  the  purpose  of  these  regulations,  fourteen  days  shall 
be  considered  as  the  period  of  incubation  of  small-pox. 

118.  On  all  vessels  arriving  with  small-pox  on  board,  or  having 
had  small-pox  on  board  during  the  voyage,  any  of  the  personnel 
who  have  been  exposed  to  the  infection  of  the  disease  must  be 
vaccinated  or  detained  in  quarantine  not  less  than  fourteen  days, 
unless  they  show  satisfactory  evidence  of  recent  successful  vacci- 
nation or  of  having  had  small-pox. 

119.  Vessels  arriving  with  small-pox  on  board  which  has  been 
properly  isolated  and  other  sufficient  precautions  taken  to  pre- 
vent the  spread  of  the  disease  need  not  be  quarantined  further 
than  the  removal  of  the  sick,  the  disinfection  of  all  compartments, 
baggage,  and  objects  that  have  been  exposed  to  the  liability  of 
infection,  and  such  vaccination  of  the  personnel  as  required  in 
paragraph  118. 

120.  On  vessels  arriving  with  small-pox  on  board  and  where 
the  proper  isolation  and  other  precautions  have  not  been  taken, 


49^  QUARANTINE. 

all  those  whom  the  quarantine  officer  believes  to  have  been  ex- 
posed to  the  infection  will  be  detained  unless  they  have  had 
smaU-pox  or  unless  they  show  satisfactory  signs  of  having  been 
properly  vaccinated  within  one  year. 

121.  Li\'ing  compartments  and  their  contents  or  any  other 
parts  of  the  vessel  exposed  to  the  infection  must  be  disinfected. 

122.  The  baggage  and  effects  of  passengers  and  crew  that  have 
been  exposed  to  the  infection  must  be  disinfected.  (See  also 
paragraph  67.) 

SPECIAL  REGULATIONS    ON  ACCOUNT   OF   TYPHUS   FEVER. 

123.  For  the  purpose  of  these  regulations  twelve  days  shall  be 
considered  as  the  period  of  incubation  of  typhus  fever. 

124.  Vessels  in  otherwise  good  sanitary  condition,  but  having 
typhus  fever  on  board  which  has  been  properly  isolated,  need  not 
be  quarantined  further  than  the  removal  of  the  sick,  and  disinfec- 
tion of  the  compartments  and  their  contents  exposed  to  infection. 

125.  If  the  case  has  not  been  isolated,  or  the  disease  has  spread 
on  board  from  person  to  person,  the  vessel  will  be  quarantined, 
the  sick  removed,  and  those  who  have  been  exposed  to  the  infec- 
tion detained  under  observ^ation. 

126.  Vessels  in  bad  sanitary  condition,  on  which  the  disease  has 
appeared,  will  be  quarantined  until  thoroughly  cleansed  and  disin- 
fected throughout ;  the  sick  will  be  cared  for  at  isolated  hospitals, 
and  those  exposed  to  the  infection  detained  under  observation. 

127.  The  baggage  and  effects  of  passengers  and  crew  that  have 
been  exposed  to  the  infection  must  be  disinfected. 

128.  Living  compartments  and  their  contents,  or  any  other 
parts  of  the  vessel  exposed  to  the  infection  must  be  disinfected, 
and  the  destruction  of  vermin  assured.     (See  also  paragraph  67.) 

SPECIAL   REGULATIONS    ON   ACCOUNT   OF   LEPROSY. 

129.  Vessels  arriving  at  quarantine  with  leprosy  on  board  shall 
not  be  granted  pratique  until  the  leper  with  his  or  her  baggage 
has  been  removed  from  the  vessel  to  the  quarantine  station. 

130.  No  alien  leper  shall  be  landed. 

131.  If  the  leper  is  an  alien  passenger  and  the  vessel  is  from  a 
foreign  port,  action  will  be  taken  as  provided  by  the  immigration 
laws  and  regulations  of  the  United  States.  And  to  this  end  the 
case  shall  be  certified  as  a  leper  and  reported  to  the  nearest  com- 
missioner of  immigration. 

132.  If  the  leper  is  an  alien  and  a  member  of  the  crew  and  the 
vessel  is  from  a  foreign  port,  said  leper  shall  be  detained  at  the 
quarantine  at  the  vessel's  expense  until  taken  aboard  by  the  same 
vessel  when  outward  bound.  Such  case  of  leprosy  should  be 
promptly  reported  to  the  collector  of  customs  at  the  port  of 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.   497 

arrival  of  the  vessel,  and  the  collector  shall  exact  a  bond  from 
the  vessel  for  the  reshipment  of  the  said  alien  leper  upon  the 
departure  of  the  vessel. 

CANADIAN  AND   MEXICAN   FRONTIERS. 

133.  When  practicable,  alien  immigrants  arriving  at  Canadian 
or  Mexican  ports  destined  for  the  United  States,  shall  be  in- 
spected at  the  Canadian  or  Mexican  port  of  arrival  by  the  United 
States  consular  or  medical  ofi&cer,  and  be  subjected  to  the  same 
sanitary  restrictions  as  are  called  for  by  the  rules  and  regulations 
governing  United  States  ports. 

134.  Inspection  cards  will  be  issued  by  the  consular  or  United 
States  medical  ofi&cer  at  the  Canadian  or  Mexican  port  of  arrival 
to  all  such  alien  immigrants,  and  labels  affixed  to  their  baggage, 
as  is  required  at  foreign  ports  in  the  case  of  those  coming  direct 
to  any  port  of  the  United  States. 

135.  If  any  person  be  found  suffering  from  a  quarantinable 
disease,  or  be  presumably  infected,  he  shall  be  denied  entry  or 
shall  be  kept  under  quarantine  observation  so  long  as  danger  of 
conveying  the  infection  exists. 

136.  Any  baggage  or  other  effects  believed  to  be  infected  shall 
be  refused  entry  unless  disinfected  in  accordance  with  these  regu- 
la.tions. 

137.  Persons  coming  from  localities  where  cholera  is  prevailing 
shall  not  be  allowed  entry  until  after  five  days  have  elapsed  since 
last  presumable  exposure  to  infection,  and  their  baggage  disin- 
fected. 

138.  During  the  quarantine  season  persons  not  positively  iden- 
tified as  immune  to  yellow  fever,  coming  from  places  where  yellow 
fever  prevails,  will  not  be  permitted  to  enter  until  they  have  been 
away  from  said  localities  five  full  days. 

139.  Persons  coming  from  localities  where  small-pox  is  pre- 
vailing shall  not  be  allowed  entry  without  vaccination,  unless  they 
are  protected  by  a  previous  attack  of  the  disease  or  a  recent  suc- 
cessful vaccination.  The  baggage  of  persons  from  such  localities 
shall  be  disinfected. 

140.  Persons  coming  from  localities  where  t3q3hus  fever  pre- 
vails in  epidemic  form  shall  not  be  allowed  entry  until  twelve 
days  have  elapsed  since  their  last  possible  exposure  to  infection 
and  the  disinfection  of  their  baggage. 

141.  Persons  coming  from  localities  where  plague  is  prevailing 
shall  not  be  allowed  entry  until  seven  days  have  elapsed  since 
their  last  possible  exposure  to  infection  and  the  disinfection  of 
their  baggage. 

142.  No  common  carrier  which  is  infected,  or  suspected  of 
being  infected,  shall  be  allowed  to  enter  the  United  States  until 
after  such  measures  have  been  taken  as  will  render  it  safe. 

32 


498  QUARANTINE. 

143.  Articles  of  merchandise,  personal  effects,  etc.,  which  are 
presumably  infected,  shall  not  be  allowed  entry  into  the  United 
States  until  after  disinfection. 

144.  Rags  gathered  and  baled  in  Canada,  accompanied  by 
affidavits  that  the  ports  or  places  where  collected  or  handled  were 
free  from  quarantinable  disease  for  thirty  days  prior  to  shipment, 
may  be  admitted  to  entry;  but  rags  from  foreign  ports  shipped 
through  Canada  shall  not  be  admitted  to  entry  unless  they  are 
accompanied  by  a  certificate  of  a  United  States  consul  or  medical 
officer  of  the  United  States  that  they  have  been  disinfected,  or 
until  after  they  have  been  unbaled  and  disinfected  at  the  port  of 
arrival. 

145.  Where  not  otherwise  specifically  stated,  the  rules  and 
regulations  for  maritime  quarantine  shall  be  applied  as  stations  on 
the  Canadian  and  Mexican  frontiers;  and  the  methods  of  disin- 

'fections  shall  be  those  prescribed  in  these  regulations. 

SPECIAL  REGULATIONS   RELATING   TO   NAVAL  VESSELS. 

146.  Vessels  of  the'U.  S.  Navy  may  be  granted  the  hereinafter 
stated  exemptions  from  quarantine  regulations,  but  are  subject  to 
quarantine  inspection  upon  arrival  at  a  port  of  the  United  States. 

147.  The  certificates  of  the  medical  officers  of  the  U.  S.  Navy 
as  to  the  sanitary  history  and  condition  of  the  vessel  and  its  per- 
sonnel may  be  accepted  for  naval  vessels  by  the  quarantine  officer 
boarding  the  vessel  in  lieu  of  an  actual  inspection. 

148.  Vessels  of  the  U.  S.  Navy  having  entered  the  harbors  of 
infected  ports,  but  having  held  no  communication  which  is  liable 
to  convey  infection,  may  be  exempted  from  the  disinfection  and 
detention  imposed  on  merchant  vessels  from  such  ports. 

INSPECTION   OF   STATE   AND   LOCAL   QUARANTINES. 

149.  In  the  performance  of  the  duties  imposed  upon  him  by  the 
act  of  February  15,  1893,  the  Surgeon-General  of  the  Public 
Health  and  Marine-Hospital  Service  shall,  from  time  to  time, 
personally  or  through  a  duly  detailed  officer  of  the  Public  Health 
and  Marine-Hospital  Service,  inspect  the  maritime  quarantines  of 
the  United  States,  State  and  local,  as  well  as  national,  for  the 
purpose  of  ascertaining  whether  the  quarantine  regulations  pre- 
scribed by  the  Secretary  of  the  Treasury  have  been  or  are  being 
complied  with.  The  Surgeon-general,  or  the  officer  detailed  by 
him  as  inspector,  shall,  at  his  discretion,  visit  any  incoming  vessel 
or  any  vessel  detained  in  quarantine,  and  all  portions  of  the  quar- 
antine establishment,  for  the  above-named  purpose,  and  with  a 
view  to  certifying,  if  need  be,  that  the  regulations  have  been  or 
are  being  enforced. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.  499 

150.  The  Surgeon-General  of  the  PubKc  Health  and  Marine- 
Hospital  Service  is  authorized,  when  in  his  discretion  such  action 
is  necessary  in  the  interest  of  the  Public  Health,  to  remand,  by 
direction  of  the  Secretary  of  the  Treasury,  any  vessel  to  the 
nearest  national.  State,  or  local  quarantine  station  provided  with 
proper  facilities  for  handling  infected  vessels. 

Disinfectants  Authorized  by  these  Regulations  and  the  Proper  Methods  of 
Generating  and  Using  Same. 

PHYSICAL   DISINFECTANTS. 

151.  Burning.  Of  unquestioned  efficiency,  but  seldom  re- 
quired. 

152.  Boiling.  Very  efficient  and  of  wide  range  of  applica- 
bility. The  articles  must  be  wholly  immersed  for  not  less  than 
thirty  minutes  in  water  actually  boiling  (100°  C).  The  addition 
of  I  per  cent,  of  carbonate  of  soda  renders  the  process  applicable 
to  polished  steel,  cutting  instruments,  or  tools. 

153.  Steam. 

{a)  Flowing  steam  (not  under  pressure).  Flowing  steam  (not 
under  pressure)  when  applied  under  suitable  conditions  is  an  effi- 
cient disinfecting,  agent.  The  exposure  must  be  continued  thirty 
minutes  after  the  temperature  has  reached  100°  C. 

ib)  Steam  under  pressure  without  vacuum.  Steam  under 
pressure  will  sterilize,  provided  that  the  process  is  continued 
twenty  minutes  after  the  pressure  reaches  15  pounds  per  square 
inch.  The  air  must  be  expelled  from  the  apparatus  at  the  begin- 
ning of  the  process.  If  impracticable  to  obtain  the  designated 
pressure,  a  longer  exposure  will  accomplish  the  same  result. 

(c)  Steam  under  pressure  with  vacuum.  Steam  in  a  special 
apparatus  with  vacuum  attachment  is  the  best  method  of  apply- 
ing steam  under  pressure,  the  object  of  the  vacuum  apparatus 
being  to  expel  the  air  and  to  promote  the  penetration  of  the  steam. 
The  process  is  to  be  continued  for  twenty  minutes  after  the  pres- 
sure reaches  10  pounds  to  the  square  inch. 


GASEOUS   DISINFECTANTS. 

154.  Sulphur  dioxid.  Sulphur  dioxid  is  efficient,  but  requires 
the  presence  of  moisture.  It  is  only  a  surface  disinfectant,  and  is 
lacking  in  penetrating  properties.  An  atmosphere  containing  4.5 
per  cent,  can  be  obtained  by  burning  5  pounds  of  sulphur  per 
1000  cubic  feet  of  space.  This  amount  would  require  the  evapo- 
ration or  volatilization  of  about  i  pint  of  water.  Under  these 
conditions  the  time  of  exposure  should  be  not  less  than  twenty- 
four  hour's  for  bacterial  infections.  A  shorter  time  will  suffice  for 
fumigation  necessary  to  kill  mosquitoes  and  other  vermin. 


500  QUARANTINE. 

155.  The  sulphur  may  be  burned  in  shallow  iron  pots  (Dutch 
ovens)  containing  not  more  than  30  pounds  of  sulphur  for  each 
pot,  and  the  pots  should  stand  in  vessels  of  water.  The  sulphur 
pots  should  be  elevated  from  the  bottom  of  the  compartment  to 
be  disinfected,  in  order  to  obtain  the  maximum  possible  per- 
centage of  combustion  of  sulphur.  The  sulphur  should  be  in  a 
state  of  fine  division,  and  ignition  is  best  accomplished  by  alco- 
hol ;  special  care  to  be  taken  with  this  method  to  prevent  damage 
to  cargo  of  vessel  by  fire ;  or  the  sulphur  may  be  burned  in  a  special 
furnace,  the  sulphur  dioxid  being  distributed  by  a  power  fan. 
This  method  is  peculiarly  applicable  to  cargo  vessels. 

156.  Liquefied  sulphur  dioxid  may  be  used  for  disinfection  in 
place  of  sulphur  dioxid  generated  as  above,  it  being  borne  in  mind 
that  this  process  will  require  2  pounds  of  the  liquefied  gas  for  each 
pound  of  sulphur  as  indicated  in  the  above  paragraphs. 

157.  Sulphur  dioxid  is  especially  applicable  to  the  holds  of  ves- 
sels, or  to  freight  cars  and  apartments  that  may  be  tightly  closed 
and  which  do  not  contain  objects  injured  by  the  gas.  Sulphur 
dioxid  bleaches  fabrics  or  materials  dyed  with  vegetable  or  anilin 
dyes.  It  destroys  linen  or  cotton  goods  by  rotting  the  fiber 
through  the  agency  of  the  acids  formed.  It  injures  most  metals. 
It  is  promptly  destructive  to  all  forms  of  animal  life.  This 
property  renders  it  a  valuable  agent  for  the  extermination  of 
rats,  insects,  and  other  vermin. 


rORMALDEHYD   GAS. 

158.  Formaldehyd  gas  is  effective  if  applied  by  one  of  the 
methods  given  below.  Formaldehyd  gas  has  the  advantage  as  a 
disinfectant  that  it  does  not  injure  fabrics  or  most  colors.  It  is 
not  poisonous  to  the  higher  forms  of  animal  life.  It  fails  to  kill 
vermin,  such  as  rats,  mice,  roaches,  bedbugs,  etc.  The  method 
is  not  applicable  to  the  holds  of  large  vessels.  Formaldehyd  is 
applicable  to  the  disinfection  of  rooms,  clothing,  and  fabrics,  but 
should  not  be  depended  upon  for  bedding,  upholstered  furniture, 
and  the  like,  when  deep  penetration  is  required.^ 

159.  Many  formaldehyd  solutions  do  not  contain  40  per  cent, 
of  formaldehyd,  and  all  are  apt  to  deteriorate  with  time.  It  is 
therefore  necessary  to  use  a  quantity  in  excess  of  the  amount  pre- 
scribed in  these  regulations,  unless  the  solution  has  been  recently 
analyzed. 

160.  The  following  methods  of  evolving  the  gas  may  be  used: 
(a)  Autoclave  under  pressure,  three  to  twelve  hours'  exposure. 
(J)  Lamp  or  generator,  six  to  eighteen  hours'  exposure. 

^  It  should  be  noted  that  formaldehyd  disinfection  is  more  efidcient  in  warm, 
moist,  or  still  weather  than  in  cold-;  dry,  or  windy  weather. 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.    50I 

(c)  Spraying,  twelve  to  twenty-four  hours'  exposure. 

{d)  Formaldehyd  and  dry  heat  in  partial  vacuum,  one  hour's 
exposure. 

i6i.  The  minimum  number  of  hours'  exposure  as  given  above 
applies  to  empty  rooms  of  tight  construction  containing  smooth, 
hard  surfaces;  the  maximum  number  of  hours'  exposure  applying 
in  all  cases  to  textiles  and  other  articles  of  a  similar  kind  requiring 
more  or  less  penetration. 

162.  Autoclave  under  pressure.  This  method  has  consider- 
able penetrating  power  when  applied  as  detailed  below.  Rooms 
or  apartments  need  no  special  preparation  beyond  the  ordinary 
closing  of  doors  and  windows.  Pasting,  caulking,  or  chinking  of 
ordinary  cracks  and  crevices  is  not  necessary.  The  doors  of 
lockers  and  closets  and  the  drawers  of  bureaus  should  be  opened. 
In  this  apparatus  use  formalin  (40  per  cent.),  with  the  addition  of 
a  neutral  salt,  such  as  calcium  chlorid  (20  per  cent.).  The  gas 
must  be  evolved  under  a  pressure  not  less  than  45  pounds.  After 
the  gas  is  separated  from  its  watery  solution  the  pressure  may  be 
allowed  to  fall  and  steam  projected  into  the  compartment  to  sup- 
ply the  necessary  moisture.  Use  not  less  than  10  ounces  of  for- 
malin per  1000  cubic  feet,  and  keep  the  room  closed  for  three  to 
twelve  hours  after  the  completion  of  the  process.  For  large 
rooms  the  gas  must  be  introduced  at  several  points  as  far  apart  as 
possible.  It  is  applicable  to  the  disinfection  of  clothing  and 
fabrics  suspended  loosely  in  such  a  manner  that  every  article  is 
freely  accessible  to  the  gas  from  all  directions. 

163.  Lamp  or  generator.  This  method  requires  an  apparatus 
producing  formaldehyd  by  a  partial  oxidation  of  wood  alcohol, 
and  in  using  it  the  room  or  apartment  should  be  rendered  tight  as 
practicable.  Oxidize  24  ounces  of  wood  alcohol  per  1000  cubic 
feet,  and  keep  the  room  closed  for  six  to  eighteen  hours,  in 
accordance  with  the  provisions  of  paragraph  165.  This  method 
leaves  little  or  no  odor.  When  applied  to  clothing  and  textiles, 
the  articles  should  be  suspended  in  a  tight  room  and  so  disposed 
as  to  permit  free  access  of  the  gas.  (See  also  paragraph  166.) 
The  wood  alcohol  shoiild  be  of  95  per  cent,  strength,  and  should 
not  contain  more  than  5  per  cent,  of  acetone. 

164.  Spraying.  The  formalin  (40  per  cent.)  should  be  sprayed 
on  sheets  suspended  in  the  room  in  such  a  manner  that  the  solu- 
tion remains  in  small  drops  on  the  sheet.  Spray  not  less  than 
10  ounces  of  formalin  (40  per  cent.)  for  each  1000  cubic  feet. 
Used  in  this  way  a  sheet  will  hold  about  5  ounces  without  drip- 
ping or  the  drops  running  together.  The  room  must  be  very 
tightly  sealed  in  disinfecting  with  this  process,  and  kept  closed 
not  less  than  twelve  hours.  The  method  is  limited  to  rooms  or 
apartments  not  exceeding  2000  cubic  feet.  The  formalin  may 
also  be  sprayed  upon  the  walls,  floors,  and  objects  in  the  rooms. 


502  QUARANTINE. 

This  method  is  markedly  interfered  with  by,  and  is  not  to  be 
relied  on  at,  low  temperatures,  say,  below  72°  F.  At  43.5°  F. 
very  little  formaldehyd  is  liberated,  the  formaldehyd  being 
polymerized  on  the  sheets. 

165.  Formaldehyd  with  dry  heat  in  partial  vacuum.  This 
method  has  superior  penetrating  powers,  and  is  specially  appli- 
cable to  clothing  and  baggage.  The  requirements  of  this  method 
are  (i)  dry  heat  of  60°  C.  sustained  for  one  hour;  (2)  a  vacuum 
of  15  inches;  (3)  formaldehyd  evolved  from  a  mixture  of  for- 
malin with  a  neutral  salt,  in  an  autoclave  under  pressure,  using 
not  less  than  30  ounces  of  formalin  (40  per  cent.)  for  1000  cubic 
feet;  and  (4)  a  total  exposure,  imder  these  combined  conditions, 
of  one  hour. 

166.  Chemical,  as — 

(i)  Formalin  permanganate  method.  When  formalin  is 
poured  over  crystals  of  permanganate  of  potash,  a  vigorous 
reaction  takes  place,  and  a  large  qviantity  of  formaldehyd  gas  is 
liberated.  Reaction  is  over  in  a  short  time,  five  minutes,  and  if  a 
proper  proportion  of  substances  is  used,  the  residue  is  almost 
dr}\  The  proportion  is  2  pints  of  formalin  to  i  pound  of  per- 
manganate of  potash.  One  pint  of  formalin  for  1000  cubic 
feet  of  space,  should  be  used  if  the  temperature  is  60°  F.  or  less, 
a  less  amount  may  be  used  for  higher  temperatures,  but  not  less 
than  10  ounces  per  1000  cubic  feet.  This  method  is  extremely 
efficient  on  account  of  the  rapidity  with  which  the  gas  is  liber- 
ated, but  the  danger  of  fire  should  be  guarded  against,  as  the 
formaldehyd  gas,  being  in  a  comparatively  dry  state,  is  inflam- 
mable in  the  presence  of  a  light,  such  as  lighted  matches,  lamp, 
etc. 

(2)  Formalin-aluminum  sulphate-lime  method.  Add  i  part 
sulphate  of  aluminum  to  2  parts  of  hot  water.  One  part  of  this 
solution  is  added  to  2  parts  of  formalin  (both  by  volume).  One 
part  of  this  second  solution  is  poured  on  2  parts  of  unslaked 
lime  (quick  lime),  broken  into  small  particles.  The  process  of 
liberation  of  formaldehyd  gas  is  completed  in  about  twenty 
minutes.  This  method  is  not  as  efficient  as  the  previous  one,  as 
less  than  half  the  amount  of  formaldehyd  gas  is  yielded  from  the 
same  amount  of  formalin. 

Two  pints  of  formalin  per  1000  cubic  feet  of  space  should  be 
used,  if  the  temperature  is  60°  F.  or  less. 

Fire  should  be  guarded  against,  but  this  danger  is  decidedly 
less  than  in  the  permanganate  process  on  account  of  the  large 
amount  of  water  vapor  coming  off  with  the  gas. 

167.  The  stated  times  of  exposure  to  sulphur  dioxid  and  for- 
maldehyd are  sufficient  to  destroy  bacterial  infection  due  to  non- 
spore-bearing  organisms,  providing  that  the  infection  is  present 
on  the  surface.     If  the  room  is  of  peculiar  construction,  so  as  to 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.    503 

impede  the  diffusion  of  the  gas,  or  if  the  room  is  a  dirty  one,  or 
if  on  account  of  any  other  condition  rendering  the  germicidal 
action  of  the  gas  more  difficult,  the  time  of  exposure  should  be 
proportionately  increased,  or  supplanted  by  other  methods. 

CHEMICAL   SOLUTIONS. 

168.  Bichlorid  of  mercury.  Bichlorid  of  mercury  is  a  disin- 
fectant of  undoubted  potency  and  wide  range  of  applicability. 
It  cannot  be  depended  upon  to  penetrate  substances  in  the  pres- 
ence of  albuminous  matter.  It  should  be  used  in  solutions  of 
I  :  1000.  The  solubility  of  bichlorid  of  mercury  may  be  increased 
by  using  sea-water  for  the  solution,  or  by  adding  2  parts  per 
1000  of  sodium  or  ammonium  chlorid  to  the  water  employed. 

169.  Carbolic  acid.  CarboHc  acid  in  the  strength  of  5  per  cent, 
(see  paragraph  52)  may  be  substituted  for  the  bichlorid  of  mer-_ 
cury,  and  should  be  employed  in  the  disinfection  of  the  cabins 
and  living  apartments  of  ships  to  obviate  injurious  action  on  pol- 
ished metals,  bright  work,  etc. 

170.  Formalin.  Formalin  containing  40  per  cent,  of  formal- 
dehyd  may  be  used  in  a  5  per  cent,  solution  as  a  substitute  for 
bichlorid  of  mercury  or  carbolic  acid,  and  is  useful  for  the  disin- 
fection of  surfaces,  dejecta,  fabrics,  and  a  great  variety  of  ob- 
jects, owing  to  its  non-injurious  character. 

Application  of  Disinfectants  in  Quarantine  Work. 

171.  Holds  of  iron  vessels,  empty,  shall  be  disinfected  by  either: 
(a)  Sulphur  dioxid  degenerated  by  burning  sulphur  5  pounds 

per  1000  cubic  feet  of  air-space,  or  liberated  from  10  pounds  of 

liquid  sulphur  dioxid,  sufficient  moisture  being  present  in  both 

cases;  time  of  exposure,  twenty-four  hours.     (See  paragraph  154.) 

{b)  Washing  with  a  solution  of  bichlorid  of  mercury,  i  :  1000. 

172.  Holds  of  wooden  vessels,  empty,  shall  be  disinfected  by: 
(a)  Sulphur  dioxid  in  the  manner  prescribed  above,  followed 

by-        . 

(&)  Washing  with  a  solution  of  bichlorid  of  mercury. 

173.  Holds  of  cargo  vessels,  when  cargo  cannot  be  removed, 
shall  be  disinfected  in  so  far  as  possible  by  sulphur  dioxid  not 
less  than  4  per  cent,  per  volume  strength,  and  where  possible 
this  should  be  generated  from  a  furnace  to  minimize  danger  of 
fire  in  cargo. 

174.  Living  apartments,  cabins,  and  forecastles  of  vessels  shall 
be  disinfected  by  one  or  more  of  the  following  methods: 

(a)  Sulphur  dioxid,  the  destructive  action  of  the  gas  on  prop- 
erty being  borne  in  mind. 
(6)  Formaldehyd  gas. 
(c)  Washing  with  solution  of  bichlorid  of  mercury,  i  :  1006  or  5 


504  QUARANTINE. 

per  cent,  solution  of  formalin,  or  5  per  cent,  solution  of  carbolic 
acid,  preference  being  given  to  carbolic  acid  for  application  to 
polished  woods,  bright  metals,  and  other  objects  injured  by  metal- 
lic salts. 

The  forecastle,  steerage,  and  other  living  apartments  in  bad 
sanitary  condition  must  be  disinfected  by  method  (a),  followed 
by  method  (c). 

175.  Mattresses,  pillows,  and  heavy  fabrics  are  to  be  disinfected 
by: 

(a)  Boiling. 

(&)  Flowing  steam — i.  e.,  steam  not  under  pressure. 

(c)  Steam  under  pressure. 

(d)  Steam  in  a  special  apparatus  with  vacuum  attachment. 

176.  Clothing,  fabrics,  textiles,  curtains,  hangings,  etc.,  may 
be  treated  by  either  of  the  above  methods  from  (a)  to  (d)  inclu- 
sive, as  circumstances  may  demand,  or  by  formaldehyd  gas  or 
sulphur  dioxid  where  the  article  is  of  a  character  which  will  not 
be  damaged  by  sulphur  dioxid. 

177.  Articles  injured  by  steam,  such  as  leather,  furs,  skins, 
rubber,  trunks,  valises,  hats  and  caps,  bound  books,  silks,  and 
fine  woolens  should  not  be  disinfected  by  steam.  Such  articles 
should  be  disinfected  by  formaldehyd  gas  or  by  any  of  the  agents 
allowed  in  these  regulations  which  may  be  applicable  thereto. 
Those  which  will  be  injured  by  wetting  should  be  disinfected  by 
a  gaseous  agent. 

178.  Clothing,  textiles,  and  baggage,  clean  and  in  good  con- 
dition, but  suspected  of  infection,  can  be  efficiently  and  least 
injuriously  disinfected  by  formaldehyd  gas,  generated  by  one  of 
the  methods  prescribed  in  paragraph  160 — (a),  (b),  or  (d). 

179.  Textiles  which  are  soiled  with  the  discharges  of  the  sick 
or  presumably  are  deeply  infected,  must  be  disinfected  by: 

(a)  Boiling. 

(b)  Steam. 

(c)  Immersion  in  one  of  the  germicidal  solutions. 

180.  Cooking  and  eating  utensils  are  always  to  be  disinfected 
by  immersion  in  boiling  water  or  by  steam. 

Agents  for  the  Destruction  of  Mosquitoes,  Rats,  and  Other  Vermin,  and  Their 
Application  to  Quarantine  Work. 

181.  Sulphur  dioxid — obtained  as  described  in  paragraphs  154 
and  155 — destroys  all  animal  life. 

182.  In  the  case  of  vessels,  when  treated  for  yellow  fever  infec- 
tion, the  process  shall  be  a  simultaneous  fumigation  with  sulphur 
dioxid,  2  per  cent,  volume  gas,  and  two  hours'  exposure,  in  order 
to  insure  the  destruction  of  mosquitoes. 

183.  In  the  case  of  vessels  when  treated  for  plague  the  process 
with  sulphur  dioxid  shall  be  as  follows: 


QUARANTINE  LAWS  OF  THE  UNITED  STATES.    505 

Without  cargo:  The  simultaneous  fumigation  with  sulphur 
dioxid  gas  not  less  than  2  per  cent,  for  six  hours'  exposure. 

With  cargo:  Fumigation  with  sulphur  dioxid  gas,  4  per  cent., 
six  to  twelve  hours'  exposure,  according  to  stowing. 

Infected  vessels  may  require  partial  or  complete  discharge  of 
cargo,  and  fractional  fumigation  for  efficient  deratization. 

184.  Pyrethrum.  The  fumes  of  burning  pyrethrum  may  be 
used  to  destroy  mosquitoes  in  places  where  there  are  articles 
liable  to  be  injured  by  the  use  of  sulphur. 

Four  pounds  per  1000  cubic  feet  space  for  two  hours'  exposure 
with  this  amount  all  or  practically  all  of  the  mosquitoes  will  be 
killed,  but  precautions  should  be  taken  to  sweep  up  and  destroy 
any  that  may  have  escaped. 

Pyrethrum  stains  walls,  paper,  etc. 

185.  The  oxids  of  carbon,  as  used  at  Hamburg,  are  efificient  to 
destroy  rats,  but  do  not  kill  fleas  or  other  insects.  They  are  ob- 
tained by  burning  carbon,  coke,  or  charcoal  in  special  apparatus, 
and  the  gas  as  produced  consists  of  about  5  per  cent,  carbon 
monoxid,  18  per  cent,  carbon  dioxid,  and  77  per  cent,  nitrogen. 

Twenty  kilos  of  carbon,  coke,  or  charcoal  are  used  for  every 
1000  meters  of  space.  The  gas  is  allowed  to  remain  in  the  ship  for 
two  hours  and  from  seven  to  eight  hours  are  allowed  for  it  to 
leave  it.  This  is  about  equivalent  to  i^  pounds  of  carbon 
(coke)  to  1000  cubic  feet  of  air  space.  As  this  gas  is  very  fatal 
to  man  and  gives  no  warning  of  its  presence,  being  odorless,  a 
small  amount  of  sulphur  dioxid  should  be  added  to  give  warning 
of  its  presence.  As  it  does  not  kill  fleas,  it  cannot  be  depended 
on  for  complete  work,  where  there  is  evidence  of  plague  among 
rats  on  the  vessel,  as  the  infected  fleas  w^ould  infect  the  rats 
coming  aboard  after  the  deratization. 

186.  The  articles  named  as  disinfectants  which  can  obviously 
destroy  animal  life  can  be  used  for  that  purpose  when  applicable, 
as  steam  for  bedding,  fabrics,  etc.  Formaldehyd  is  not  appli- 
cable for  this  purpose. 

187.  Where  both  disinfection  and  destruction  of  vermin  are 
required  for  mattresses,  pillows,  and  fabrics,  the  use  of  steam 
meets  both  requirements,  and  is  especially  applicable. 

188.  Hydrocyanic  acid  gas  is  fatal  to  all  forms  of  animal  life 
and  is  not  injurious  to  any  material.  It  is  best  generated  by 
mixing — 

Cyanid  of  potash 4 

Sulphuric  acid 6 

Water 9 

The  acid  should  first  be  diluted,  which  must  be  done  in  some 
vessel  capable  of  withstanding  the  heat.  The  whole  amount  of 
the  cyanid  of  potash  must  be  put  in  the  acid  at  once,  and  as  the 


5o6  QUARANTINE: 

evolution  of  the  gas  is  very- rapid,  the  operator  must  be  prepared 
to  leave  immediately.  Fulton  advises  that  the  cyanid  be  tied  in 
a  bag,  to  be  lowered  into  the  acid  by  a  cord  passing  outside  of  the 
room. 

About  ID  ounces  of  cyanid  of  potash  per  looo  cubic  feet. 

It  is,  of  course,  applicable  when  necessary  to  destroy  mosquitoes 
or  vermin  (particularly  in  living  quarters),  but  is  too  dangerous  to 
be  used  except  by  those  experienced  in  its  use,  and  then  under 
most  rigid  precautions.  Though  destructive  to  animal  life,  hy- 
drocyanic acid  gas  is  but  of  slight  value  as  a  germicide. 

INTERSTATE    QUARANTINE. 

All  interstate  quarantiije  powers  of  the  United  States 
have  also  been  conferred  upon  the  Supervising  Surgeon- 
General  of  the  IMarine-Hospital  Service.  The  following 
is  a  transcript  of  the  act  of  Congress  conferring  these 
powers  and  the  interstate  quarantine  regulations: 

[Act  of  March  27,  1890.] 

An  Act  to  prevent  the  introduction  of  contagious  diseases  from 
one  State  to  another,  and  for  the  punishment  of  certain  offences. 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  assembled,  That  whenever 
it  shall  be  made  to  appear  to  the  satisfaction  of  the  President  that 
cholera,  yellow  fever,  small-pox,  or  plague  exists  in 'any  State  or 
territory,  or  in  the  District  of  Columbia,  and  that  there  is  danger 
of  the  spread  of  such  disease  into  other  States,  territories,  or  the 
District  of  Columbia,  he  is  hereby  authorized  to  cause  the  Secre- 
tary of  the  Treasury  to  promulgate  such  rules  and  regulations  as 
in  his  judgment  may  be  necessary  to  prevent  the  spread  of  such 
disease  from  one  State  or  territory  into  another,  or  from  any  State 
or  territory  into  the  District  of  Columbia,  or  from  the  District  of 
Columbia  into  any  State  or  territory,  and  to  employ  such  regula- 
tions to  prevent  the  spread  of  such  disease.  The  said  rules  and 
regulations  shall  be  prepared  by  the  Supervising  Surgeon-General 
of  the  Marine-Hospital  Service,  under  the  direction  of  the  Secre- 
tary of  the  Treasury.  And  any  person  who  shall  wilfully  violate 
any  rule  or  regulation  so  made  and  promulgated  shall  be  deemed 
guilty  of  a  misdemeanor,  and  upon  conviction  shall  be  punished 
by  a  fine  of  not  more  than  five  hundred  dollars,  or  imprisonment 
for  not  more  than  two  years,  or  both,  in  the  discretion  of  the 
court. 

Sec.  2.  That  any  officer,  or  person  acting  as  an  officer,  or  agent 
of  the  United  States  at  any  quarantine  station,  or  other  person 
employed  to  aid  in  preventing  the.  spread  of  such  disease,  who 


INTERSTATE  QUARANTINE  REGULATIONS.     507 

shall  wilfully  violate  any  of  the  quarantine  laws  of  the  United 
States,  or  any  of  the  rules  and  regulations  made  and  promulgated 
by  the  Secretary  of  the  Treasury,  as  provided  for  in  Section  i  of 
this  act,  or  any  lawful  order  of  his  superior  officer  or  officers, 
shall  be  deemed  guilty  of  a  misdemeanor,  and  upon  conviction 
shall  be  punished  by  a  fine  of  not  more  than  three  hundred  dollars, 
or  imprisonment  for  not  more  than  one  year,  or  both,  in  the  dis- 
cretion of  the  court. 

Sec.  3.  That  when  a  common  carrier,  or  officer,  agent,  or 
employe  of  any  common  carrier,  shall  wilfully  violate  any  of  the 
quarantine  laws  of  the  United  States,  or  the  rules  and  regulations 
made  and  promulgated  as  provided  for  in  Section  1  of  this  act, 
such  common  carrier,  officer,  agent,  or  employe  shall  be  deemed 
guilty  of  a  misdemeanor,  and  shall,  on  conviction,  be  punished 
by  a  fine  of  not  more  than  five  hundred  dollars,  or  imprisonment 
for  not  more  than  two  years,  or  both,  in  the  discretion  of  the 
court. 


INTERSTATE  QUARANTINE  REGULATIONS. 

Article  I. 

QUARANTINABLE    DISEASES. 

(i)  For  the  purposesvof  these  regulations  the  quarantinable  dis- 
eases are  cholera  (cholerine),  yellow  fever,  small-pox,  typhus  fevei, 
leprosy,  and  plague. 

Article  II. 

NOTIFICATION. 

(i)  State  and  municipal  health  officers  should  immediately 
notify  the  Supervising  Surgeon-General  of  the  U.  S.  Marine-Hos- 
pital Service  by  telegraph  or  by  letter  of  the  existence  of  any  of 
the  above-mentioned  quarantinable  diseases  in  their  respective 
States  or  localities, 

Article  III. 

GENERAL   REGULATIONS. 

(i)  Persons  suffering  from  a  quarantinable  disease  shall  be 
isolated  until  no  longer  capable  of  transmitting  the  disease  to 
others.  Persons  exposed  to  the  infection  of  a  quarantinable  dis- 
ease shall  be  isolated,  under  observation,  for  such  a  period  of  time 
as  may  be  necessary  to  demonstrate  their  freedom  from  the  disease. 

All  articles  pertaining  to  such  persons,  liable  to  convey  infec- 
tion, shall  be  disinfected  as  hereinafter  provided. 

(2)  The  apartments  occupied  by  persons  suffering  from  quaran- 
tinable disease,  and  adjoining  apartments  when  deemed  infected, 
together  with  articles  therein,  shall  be  disinfected  upon  the  ter- 
mination of  the  disease. 


508  QUARANTINE. 

(3)  Communication  shall  not  be  held  with  the  above-named 
persons  and  apartments,  except  under  the  direction  of  a  duly 
qualified  officer. 

(4)  All  cases  of  quarantinable  disease,  and  all  cases  suspected 
of  belonging  to  this  class,  shall  be  at  once  reported  by  the  physi- 
cian in  attendance  to  the  proper  authorities. 

(5)  No  common  carrier  shall  accept  for  transportation  any  per- 
son suffering  with  a  quarantinable  disease,  nor  any  infected  article 
of  clothing,  bedding,  or  personal  property. 

The  body  of  any  person  who  has  died  of  a  quarantinable  dis- 
ease shall  not  be  transported  save  in  hermetically  sealed  coffins, 
and  by  the  order  of  the  State  or  local  health  officer. 

(6)  In  the  event  of  the  prevalence  of  small-pox,  all  persons 
exposed  to  the  infection,  who  are  not  protected  by  vaccination  or 
a  previous  attack  of  the  disease,  shall  be  at  once  vaccinated  or 
isolated  for  a  period  of  fourteen  days. 

(7)  During  the  prevalence  of  cholera  all  the  dejecta  of  cholera 
patients  shall  be  at  once  disinfected  as  hereinafter  provided,  to 
prevent  possible  contamination  of  the  food-  and  water-supply. 

Article  IV. 

YELLOW    FEVER. 

In  addition  to  the  foregoing  regulations  contained  in  Article 
III.  the  following  special  provisions  are  made  with  regard  to  the 
prevention  of  the  introduction  and  spread  of  yellow  fever  : 

(i)  Localities  infected  with  yellow  fever,  and  localities  contig- 
uous thereto,  should  be  depopulated  as  rapidly  and  as  completely 
as  possible,  so  far  as  the  same  can  be  safely  done ;  persons  from 
non-infected  localities  and  who  have  not  been  exposed  to  infec- 
tion being  allowed  to  leave  without  detention.  Those  who  have 
been  exposed,  or  who  come  from  infected  localities,  shall  be  re- 
quired to  undergo  a  period  of  detention  and  observation  of  ten 
days  from  the  date  of  last  exposure  in  a  camp  of  probation  or 
other  designated  place. 

Clothing  and  other  articles  capable  of  conveying  infection  shall 
not  be  transported  to  non-infected  localities  without  disinfection. 

(2)  Persons  who  have  been  exposed  may  be  permitted  to  pro- 
ceed without  detention  to  localities  incapable  of  becoming  in- 
fected and  whose  authorities  are  willing  to  receive  them  and  after 
arrangements  have  been  perfected,  to  the  satisfaction  of  the  proper 
health  officer,  for  their  detention  in  said  localities  for  a  period  of 
ten  days. 

(3)  The  suspects  who  are  isolated  under  the  provisions  of  para- 
graph I,  Article  III.,  shall  be  kept  free  from  all  possibility  of 
infection. 

(4)  So  far  as  possible,  the  sick  should  be  removed  to  a  central 
location  for  treatment. 

(5)  Buildings  in  which  yellow  fever  has  occurred,  and  localities 


INTERSTATE  QUARANTINE  REGULATIONS.     509 

believed  to  be  infected  with  said  disease,  must  be  disinfected  as 
thoroughly  as  possible. 

(6)  As  soon  as  the  disease  becomes  epidemic  the  railroad  trains 
carr\-ing  persons  allowed  to  depart  from  a  city  or  place  infected 
with  yellow  fever  shall  be  under  medical  supervision. 

(7)  Common  carriers  from  the  infected  districts,  or  believed  to 
be  carr}-ing  persons  and  effects  capable  of  conveying  infection, 
shall  be  subject  to  a  sanitary  inspection,  and  such  persons  and 
effects  shall  not  be  allowed  to  proceed,  except  as  provided  for 
by  paragraph  2. 

(8)  At  the  close  of  an  epidemic  the  houses  where  sickness  has 
occurred,  and  the  contents  of  the  same,  and  houses  and  contents 
that  are  presumably  infected,  shall  be  disinfected  as  hereinafter 
prescribed. 

Article  V. 

DISINFECTION. 
FOR    CHOLERA. 

(i)  The  dejecta  and  vomited  matters  of  cholera  patients  shall 
be  received  into  vessels  containing  an  acid  solution  of  bichlorid  of 
mercury  (bichlorid  of  mercury,  i  part ;  hydrochloric  acid,  2 
parts;  water,  1000  parts)  or  other   efficient  germicidal  agent. 

(2)  All  bedding,  clothing,  and  wearing  apparel  soiled  by  the 
discharges  of  cholera  patients  shall  be  disinfected  by  one  or  more 
of  the  following  methods  : 

{ci)  By  complete  immersion  for  thirty  minutes  in  one  of  the 
above-named  disinfecting  solutions. 

(b  \  By  boiling  for  fifteen  minutes  ;  all  articles  to  be  completely 
submerged. 

(r)  By  exposure  to  steam  at  a  temperature  of  100°  to  102°  C. 
for  thirty  minutes  after  such  temperature  is  reached. 

(3)  Any  woodwork  or  furniture  contaminated  by  cholera  dis- 
charges shall  be  disinfected  by  thorough  washing  with  a  germi- 
cidal solution,  as  provided  in  paragraph  i,  Article  III. 

FOR    YELLOW    FEVER. 

(4)  Apartments  infected  by  occupancy  of  patients  sick  with 
yellow  fever  shall  be  disinfected  by  one  or  more  of  the  following 
methods : 

{a)  By  thorough  washing  with  one  of  the  above-named  germi- 
cidal solutions.  If  apprehension  is  felt  as  to  the  poisonous  effects 
of  the  mercury,  the  surfaces  may,  after  two  hours,  be  washed  with 
clear  water. 

{b~)  Thorough  washing  wath  a  5  per  cent,  solution  of  pure  car- 
bolic acid. 

(r)  By  sulphur  dioxid,  twenty-four  to  forty-eight  hours'  ex- 
posure, the  apartments  to  be  rendered  as  air-tight  as  possible. 


5  lO  QUARANTINE. 

(5)  Bedding,  wearing  apparel,  carpets,  hangings,  and  draperies 
infected  by  yellow  fever  shall  be  disinfected  by  one  of  the  follow- 
ing methods : 

{a)  By  exposure  to  steam  at  a  temperature  of  100°  to  102°  C. 
for  thirty  minutes  after  such  temperature  is  reached. 

(J?)  By  boiling  for  fifteen  minutes  3  all  articles  to  be  completely 
submerged. 

{c)  By  thorough  saturation  in  a  solution  of  bichlorid  of  mer- 
cury I  :  1000,  the  articles  being  allowed  to  dry  before  washing. 

Articles  injured  by  steam  (rubber,  leather,  containers,  etc.),  to 
the  disinfection  of  which  steam  is  inapplicable,  shall  be  disinfected 
by  thoroughly  wetting  all  surfaces  with  {a)  a  solution  of  bichlorid 
of  mercury  i  :  800,  or  {b)  a  5  per  cent,  solution  of  carbolic  acid, 
the  articles  being  allowed  to  dry  in  the  open  air  prior  to  being 
washed  with  water,  or  (^)  by  exposure  to  sulphur  fumigation  in  an 
apartment  air-tight,  or  as  nearly  so  as  possible. 

FOR   SMALL-POX. 

(6)  Apartments  infected  by  small-pox  shall  be  disinfected  by 
one  or  both  of  the  following  methods : 

(d)  Exposure  to  sulphur  dioxid  for  twenty-four  to  forty-eight 
hours. 

(J?)  Washing  with  a  solution  of  bichlorid  of  mercury,  i  :  1000, 
or  a  5  per  cent,  solution  of  pure  carbolic  acid. 

(7)  Clothing,  bedding,  and  articles  of  furniture  exposed  to  the 
infection  of  small-pox  shall  be  disinfected  by  one  or  more  of  the 
following  methods : 

{a)  Exposure  to  sulphur  dioxid  for  twenty-four  to  forty-eight 
hours.    , 

{F)  Immersion  in  a  solution  of  bichlorid  of  mercury,  i  :  1000, 
or  5  per  cent,  solution  of  pure  carbolic  acid. 

{c)  Exposure  to  steam  at  a  temperature  of  100°  to  102°  C.  for 
thirty  minutes  after  such  temperature  is  reached. 

{d^  Boiling  for  fifteen  minutes ;  the  articles  to  be  completely 
submerged. 

FOR   TYPHUS    FEVER. 

(8)  Apartments  infected  by  typhus  fever  shall  be  disinfected  by 
one  or  both  of  the  following  methods : 

{a)  Exposure  to  sulphur  dioxid  for  twenty-four  to  forty-eight 
hours. 

{h)  Washing  with  a  solution  of  bichlorid  of  mercury,  i  :  1000, 
or  a  5  per  cent,  solution  of  pure  carbolic  acid. 

(9)  Clothing,  bedding,  and  articles  of  furniture  exposed  to  the 
infection  of  typhus  fever  shall  be  disinfected  by  one  or  more  of 
the  following  methods : 

{a)  Exposure  to  sulphurdioxid  for  twenty-four  to  forty-eight  hours. 
{p)  Immersion  in  a  solution  of  bichlorid  of  mercury,  i  :  1000, 
or  a  5 "per  cent,  solution  of  pure  carbolic  acid. 


STATE  QUARANTINE  REGULATIONS.  51 1 

{/)  Exposure  to  steam  at  a  temperature  of  100°  to  102°  C.  for 
thirty  minutes  after  such  temperature  is  reached. 

{ci)  Boiling  for  fifteen  minutes ;  the  articles  to  be  completely 
submerged. 

INTERSTATE  QUARANTINE  REGULATIONS  TO  PRE- 
VENT THE  SPREAD  OF  PLAGUE  IN  THE  UNITED 
STATES. 

In  accordance  with  the  provisions  of  the  act  of  March  27,  1890, 
the  following  regulations,  additional  to  existing  interstate  quaran- 
tine regulations,  are  hereby  promulgated  to  prevent  the  intro- 
duction of  plague  into  any  one  State  or  territory  or  the  District 
of  Columbia,  from  another  State  or  territory  or  the  District  of 
Columbia : 

1.  During  the  existence  of  plague  at  any  point  in  the  United 
States  the  Surgeon-Generai  of  the  Marine-Hospital  Service  is 
authorized  to  forbid  the  sale  or  donation  of  transportation  by 
common  carrier  to  Asiatics  or  other  races  particularly  liable  to  the 
disease. 

2.  No  common  carrier  shall  accept  for  transportation  any  per- 
son suffering  with  plague  or  any  article  infected  therewith,  nor 
shall  common  carriers  accept  for  transportation  any  class  of  per- 
sons who  may  be  designated  by  the  Surgeon-General  of  the  Marine- 
Hospital  Service  as  being  likely  to  convey  the  risk  of  plague  con- 
tagion to  other  communities,  and  said  common  carriers  shall  be 
subject  to  inspection. 

3.  The  body  of  any  person  who  has  died  of  plague  shall  not 
be  transported  except  in  an  hermetically  sealed  coffin  and  by 
consent  of  the  local  health  office,  in  addition  to  the  local  repre- 
sentatives of  the  Marine-Hospital  Service.  Wherever  possible, 
such  bodies  should  be  cremated. 


STATE  QUARANTINE  REGULATIONS. 

Many  of  the  seaboard  States  of  the  Union  have  quar- 
antine boards  and  stations  in  addition  to  those  of  the 
national  government.  In  1893  the  legislature  of  Penn- 
sylvania passed  a  law  establishing  the  State  Quarantine 
Board  for  the  Port  of  Philadelphia. 

As  early  as  1708,  "An  act  to  prevent  sickly  vessels 
coming  into  this  government"  was  passed  by  the  co- 
lonial assembly,  prohibiting  every  unhealthy  or  sickly 
ship  from  an  unhealthy  or  sickly  place  from  coming 
nearer  than  one  mile  to  any  of  the  towns  or  ports  of  the 
province  or  territories  without  clean  bills  of  health.  .  This 


512  Q  UARANTINE. 

act  remained  in  force  until  January  22,  i744-'  About  the 
year  1742  a  quarantine  station  was  located  at  Fisher's 
Island,  subsequently  called  Province,  and  State  Island. 
In  1749  the  trustees  of  Province  Island  were  directed  to 
build  an  hospital  or  pest-house  for  the  reception  of 
strangers  imported  into  the  province.  During  the  period 
of  the  revolutionary  war  commerce  had  so  dwindled  that 
there  was  very  little  necessity  for  a  quarantine  station. 
The  hospital,  however,  was  used  for  the  care  of  sick 
persons  sent  from  army  boats. 

The  invasion  of  yellow  fever  was  instrumental  in 
causing  an  order  to  be  given  for  the  repairment  of  the 
hospital  upon  State  Island  for  the  admission  of  patients 
and  the  appointment  of  a  resident  physician.  A  resident 
physician  was  appointed  at  the  hospital,  and  vessels 
coming  up  the  river  were  ordered  to  anchor  for  a  visit. 

In  1799  the  quarantine  station  was  located  at  Tinicum 
Island,  and  the  removal  took  place  in  1801,  at  which 
place  it  was  maintained  until  1895,  when  it  was  removed 
to  Marcus  Hook,  its  present  location.  The  service  at 
State  station,  because  of  the  two  national  quarantine 
stations  (Cape  Henlopen  and  Reedy  Island),  is,  for  the 
present,  one  of  observation  or  inspection  only,  there 
being  no  provision  for  detention  or  disinfection.  If 
sickne.ss  of  a  communicable  nature  is  discovered  on  a 
vessel,  or  if  circumstances  lead  to  the  suspicion  that  the 
vessel  herself  is  infected,  she  is  simply  remanded  to  the 
Federal  quarantine  station. 

The  right  to  quarantine  resides  with  the  individual 
States,  though  the  Federal  government  has  the  right  to 
control  in  such  matters  through  its  right  to  regulate 
interstate  commerce.  It  should  have  control  of  the 
matter  of  inland  quarantine  to  the  extent  of  directing 
and  superintending  the  measures  adopted,  in  order  to 
prevent  the  confusion  arising  from  conflicting  regula- 
tions of  the  authorities  of  adjacent  localities.  In  order 
to  secure  more  uniformity  in  the  measures  adopted. 
Congress  has  been  petitioned  time  and  again  to  pass  a 


HOUSE  QUARANTINE.  513 

law  providing  for  the  organization  of  a  National  Board 
of  Health. 

The  regulations  of  the  various  State  boards  of  health 
are  directed  toward  the  prevention  of  the  introduction  of 
infected  individuals  and  materials  from  other  States  or 
countries  and  toward  the  control  of  infection  within  the 
borders  of  the  State. 

Notwithstanding  the  fact  that  the  national  government 
has  taken  over  a  number  of  the  State  quarantine  stations 
along  the  seaboard,  several  of  the  States  still  maintain 
inspection  and  quarantine  stations  at  ports  of  entry, 
namely  :  Maryland,  Massachusetts,  New  York,  Pennsyl- 
vania, and  Texas. 

The  institution  of  quarantine  by  one  State  against  a 
neighboring  State  is  specifically  provided  for  in  the  laws 
of  California,  Connecticut,  Georgia,  Indiana,  Illinois, 
Kansas,  Kentucky,  lyouisiana,  Maine,  Marylaijd,  Massa- 
chusetts, Michigan,  Minnesota,  Mississippi,  Missouri, 
Nebraska,  New  Hampshire,  New  Jersey,  New  Mexico, 
North  Carolina,  Ohio,  Oklahoma,  Oregon,  Pennsylvania, 
Tennessee,  Virginia,  West  Virginia,  and  Wyoming. 

In  recent  years  these  interstate  quarantine  laws  have 
rarely  been  required  to  control  any  infectious  disease, 
because,  in  most  States,  the  local  quarantine  regulations 
have  been  sufficient  to  keep  infectious  diseases  under 
control. 

House  Quarantine. — The  diseases  against  which 
house  quarantine  is  directed  differ  in  different  State 
laws,  some  requiring  modified  quarantine  in  some  dis- 
eases and  in  others  simply  a  reporting  of  the  diseases  and 
placarding  of  the  houses.  Strict  quarantine  is  main- 
tained by  all  the  States  against  small-pox,  scarlet  fever, 
and  diphtheria.  Many  of  the  States  include  in  this  list 
Asiatic  cholera,  yellow  fever,  typhus  fever,  and  bubonic 
plague. 

With  regard  to  many  of  the  other  communicable  dis- 
eases, practices  differ  very  much.     The  following  diseases 
are  reportable  in  most  of  the  States :  Measles,  typhoid 
33 


514  QUARANTINE. 

fever,  epidemic  cerebrospinal  meningitis,  tuberculosis, 
and  leprosy.  In  the  following  diseases  placarding  is 
usually  required,  or  a  modified  quarantine  is  instituted, 
namely :  Whooping-cough,  mumps,  chicken-pox,  and 
German  measles.  In  addition,  the  following  diseases 
are  reportable  in  some  of  the  States :  Epidemic  dysen- 
tery, dengue,  anthrax,  glanders,  pneumonia,  tetanus  and 
relapsing  fever,  and  puerperal  fever.  In  the  regulations 
of  many  of  the  States  membranous  croup  is  classified 
under  diphtheria,  and  the  regulations  that  pertain  to 
diphtheria  are  applied  to  cases  of  so-called  membranous 
croup.  Likewise,  in  Pennsylvania  and  California,  Cuban 
or  Manila  itch  are  reportable.  In  addition  to  this,  actino- 
mycosis is  reportable  in  Pennsylvania,  h3^drophobia  in 
lyouisiana,  ophthalmia  neonatorum  in  Nebraska  and  New 
York,  uncinariasis  in  California,  and  erysipelas  in  Penn- 
sylvania. All  of  the  States  require  the  reporting  of 
anterior  poliom^-elitis. 

House  quarantine  differs  considerably  in  different  States 
and  cities.  The  statutes  of  New  York  define  as  quaran- 
tinable  "yellow  fever,  measles,  cholera,  typhus  fever, 
small-pox,  scarlet  fever,  diphtheria,  relapsing  fever,  and 
any  disease  of  a  contagious,  infectious,  or  pestilential 
character,  which  shall  be  considered  by  the  health  officer 
dangerous  to  the  public  health. ' ' 

In  New  York  City  every  case  of  contagious  disease 
reported  to  the  health  department  is  regularly  inspected 
by  the  medical  inspector  assigned  to  the  district  in  which 
it  occurs.  When  consent  can  be  obtained,  the  cases  are 
removed  to  the  department  hospitals.  In  the  tenement- 
house  districts  an  effort  is  always  made  to  induce  patients 
suffering  from  such  diseases  to  enter  the  hospitals,  and, 
if  the  conditions  are  such  as  to  require  it,  removal  to  the 
hospitals  is  enforced.  After  completion  of  the  illness  or 
transfer  of  the  patient,  thorough  disinfection  is  made 
of  the  house  or  apartment,  and  all  infected  materials  are 
removed  to  the  disinfecting  station  for  destruction  or 
disinfection    by   steam,   when   they  are  returned  to   the 


HOUSE  QUARANTINE.  515 

owner.  No  charge  is  made  for  these  services,  and  disin- 
fection is  compulsory  in  every  case.  The  practice  in 
Philadelphia  and  other  large  cities  is  quite  similar  to  that 
in  New  York. 

The  infectious  diseases  in  which  notification  is  compul- 
sory in  Philadelphia  are  :  Cholera,  small-pox,  diphtheria, 
diphtheritic  croup,  membranous  croup,  scarlet  fever,  mea- 
sles, typhoid  fever,  typhus  fever,  epidemic  cerebrospinal 
fever,  relapsing  fever,  and  leprosy.  Knowledge  of  cases 
of  diphtheria  reaches  the  department  of  health  through 
the  forwarding  of  a  culture  to  the  bacteriologic  laboratory 
for  examination,  as  well  as  by  notification  by  the  physi- 
cian. If,  on  examination,  the  culture  is  found  to  con- 
tain diphtheria  bacilli,  the  case  is  at  once  reported  to  the 
medical  inspector,  at  the  same  time  that  a  report  is  for- 
warded to  the  attending  physician.  In  this  manner 
doubtful  cases  are  diagnosed  early,  and  no  hardships  are 
entailed  upon  the  suspect  or  the  family,  while  the  com- 
munity is  protected  by  prompt  isolation  of  all  such  cases. 
The  contagious  character  of  tuberculosis  in  all  its  forms 
is  becoming  more  and  more  generally  recognized.  Never- 
theless there  is  strenuous  opposition  from  many  sources 
to  the  notification  of  cases  of  tuberculosis.  In  New 
York  and  Philadelphia  such  notification  is  now  required, 
not  with  the  idea  of  quarantining  the  cases,  but  in  order 
to  keep  informed  as  to  their  location,  and  to  make  it 
possible  to  direct  approved  prophylactic  measures  against 
the  spread  of  the  disease  from  the  sick  to  the  well.  No 
general  disinfection  of  the  premises  occupied  by  cases  of 
tuberculosis  in  the  tenement  district  is  attempted.  On 
the  other  hand,  all  such  premises  are  thoroughly  reno- 
vated after  the  removal  or  death  of  the  tubercular 
patient.  In  this  manner  the  danger  from  infection 
through  infective  dust  is  greatly  lessened.  The  work  of 
the  department  is  hampered,  however,  because  of  the 
absence  of  sufficient  hospital  accommodations  for  con- 
sumptive poor.  Most  beneficial  effects  have,  however, 
already  resulted  from  the  various  measures  instituted  for 


5 1 6  Q  UARANTINE. 

the  prevention  of  tubercnlosis,  as  shown  in  the  very  ma- 
terial decline  in  the  number  of  deaths  occurring  from  it. 
The  investigations  of  Anders  and  of  Flick,  of  Phila- 
delphia, and  those  of  Biggs,  of  New  York,  show  that 
tuberculosis  is  not  uniformly  diffused  through  a  com- 
munity, not  even  in  those  localities  where  it  occurs  most 
frequently,  but  is  confined  largely  within  narrow  bound- 
aries, as  in  certain  streets  and  within  the  walls  of  certain 
houses.  These  investigations  have  shown  that  when  a 
house  is  once  infected,  repeated  cases  are  developed  in  it 
from  the  new  tenants  occupying  such  a  house.  These 
infected  houses  are  most  frequently  found  in  the  narrower 
streets,  in  courts,  and  in  alleys.  Though  there  is  some 
danger  of  infection  from  the  inhalation  of  dust  in  the 
open  air  in  crowded  parts  of  the  city,  it  seems  probable 
that  a  more  prolonged  exposure  to  a  concentrated  atmos- 
phere of  infection,  as  found  in  these  infected  houses,  is 
the  most  frequent  mode  of  contracting  the  disease.  The 
dust  in  street-cars  and  various  public  places  is  often 
infected,  and  may  lead  to  contraction  of  the  disease. 
The  prohibition  of  spitting  on  the  floor  of  cars,  ferry- 
boats, and  other  public  conveyances  should,  therefore, 
be  strictly  enforced  as  a  wise  sanitary  measure. 


CHAPTER   XX. 
VITAL   STATISTICS. 

ViTAiv  statistics  includes  the  records  of  all  circum- 
stances affecting  the  production  and  duration  of  human 
life,  and  corresponds  to  the  term  "demographic"  em- 
ployed by  French  writers.  The  registration  of  vital 
statistics  includes  the  obtaining  of  records  of  births, 
deaths,  marriages,  and  disease.  The  comparison  of  these 
records  with  each  other,  and  with  the  statistics  of  the 
living  population,  comprises  vital  statistics  proper. 

The  systems  of  registration  employed  by  different 
States  and  cities  differ  as  to  details.  They  include  a 
periodical  report  of  the  births,  with  date  and  place  of 
birth,  sex,  color,  and  nationality  of  the  child,  and  the 
names,  residence,  birthplace,  age,  and  occupation  of  the 
parents.  These  reports  are  usually  made  monthly  by 
the  physician  to  the  health  bureau  of  the  city.  Deaths 
are  reported  through  the  physician  and  undertaker  to  the 
health  authorities,  who  issue  a  burial  permit.  The  in- 
formation furnished  on  the  death  certificate  includes  the 
age,  sex,  color,  nationality,  and  conjugal  condition  of  the 
deceased,  as  well  as  the  immediate  and  remote  causes 
of  death.  In  the  United  States  the  physician  acts  in  a 
judicial  capacity  in  reporting  a  death.  Upon  this  fact 
is  based  the  right  of  legislation  regulating  the  education 
and  qualification  of  medical  men  and  the  laws  regulating 
the  practice  of  medicine.  He  is  a  State  officer  in  relation 
to  his  knowledge  of  the  cause  of  death. 

The  cases  of  infectious  diseases  are  reported  at  once  by 
the  physician  when  the  diagnosis  has  established  the 
nature  of  the  disease.  Up  to  the  present  time  only  a 
few  States  have  had  an  accurate  system  of  registration. 
With  the  beginning  of  the  twentieth  century  a  number 

517 


5i8  VITAL  STATISTICS. 

of  States  and  cities,  as  well  as  a  large  number  of  other 
countries,  adopted  a  uniform  system  of  classification 
of  the  causes  of  death,  known  as  the  Bertillon  system. 
This  system  has  been  adopted  generally  after  repeated 
conferences  extending  over  a  number  of  years.  Dr.  Ber- 
tillon presented  his  system  of  classification  to  the  Inter- 
national Statistical  Institute  at  Chicago  in  1893.  It  has 
since  received  the  endorsement  of  the  American  Public 
Health  Association,  the  International  Conference  of  State 
and  Provincial  Boards  of  Health  of  North  America,  and 
received  its  first  International  Decennial  Revision  at 
Paris  in  1900.  By  the  use  of  this  uniform  system  of 
classification  the  vital  statistics  of  different  countries  will 
be  readily  comparable.  It  is  safe  to  presume  that  the 
general  adoption  of  such  a  uniform  system  of  classifica- 
tion, with  decennial  revisions  of  the  same  by  those  using 
it,  will  lead  to  more  efficient  registration  methods 
wherever  the  system  is  employed.  Full  information  as 
to  the  details  of  the  Bertillon  system  of  classification  may 
be  found  in  the  publications  of  the  American  Public 
Health  Association,  of  the  Michigan  Division  of  Vital 
Statistics,  and  the  United  States  Marine-Hospital  Service. 
Requiring  a  permit  for  burial  is  the  only  reliable  means 
of  obtaining  the  desired  information.  This  is  necessary 
to  secure  a  proper  inheritance  of  property.  It  also  aids 
in  detecting  crime. 

By  means  of  an  accurate  system  of  registration  a  com- 
munity is  able  to  keep  informed  as  to  the  condition  of  the 
public  health,  the  efficiency  of  quarantine  measures,  the 
purity  of  the  water-supply,  and  the  death-rate  from  all 
diseases.  The  value  of  estimates  made  from  vital  statis- 
tics as  reported  to  the  health  authorities  is  dependent 
upon  a  knowledge  of  the  living  population.  In  most 
countries  this  is  determined  decennially  by  means  of  a 
national  census.  Some  cities  have  an  additional  census 
taken  midway  between  the  decennial  censuses.  In  the 
absence  of  such  special  censuses  the  calculations  are 
based    on   the   results  of   the  decennial    censuses.     The 


STANDARDS  OF  AGE-DISTRIBUTION.  5^9 

Registrar-General  of  Scotland  employs  the  following 
method  for  calculating  the  population  for  the  inter-census 
years:  He  assumes  that  the  rate  of  increase  as  ascertained 
from  the  two  enumerations  imm2diately  preceding  con- 
tinues the  same  during  the  course  of  the  next  ten  years. 
The  sanitary  department  of  Glasgow  ascertains  the  num- 
ber of  houses  inhabited  by  the  census  population,  the 
average  population  per  house,  and  then  in  each  succeeding 
inter-census  year  applies  this  average  as  a  multiplier  to 
the  inhabited  houses  for  the  year,  as  entered  upon  the 
rolls  of  the  assessor.  Neither  of  these  methods  gives 
accurate  results.  Since  population  increases  in  geo- 
metric proportion,  the  arithmetical  mean  may  be  taken 
between  two  censuses.  The  result  will  generally  be  less 
than  normal,  but  will  not  vary  more  than  i  per  looo  in 
the  death-rate  as  calculated  from  these  data  as  compared 
with  the  results  obtained  from  actual  enumerations. 

The  Census  as  a  Basis  for  Calculation. — It  is 
essential,  therefore,  that  an  accurate  census  of  the  popula- 
tion be  taken  at  stated  intervals  to  form  the  basis  of  cal- 
culation of  the  results  obtained  from  registrations  of 
births,  deaths,  marriages,  and  disease.  The  density  of 
population,  or  the  number  of  persons  occupying  a  definite 
area,  is  also  of  value,  and  this  is  obtained  by  dividing 
the  population  by  the  area  in  square  meters,  square  miles, 
or  in  acres. 

Standards  of  Age -distribution. — In  order  to  make 
it  possible  to  secure  fair  comparisons  of  the  death-rates 
of  different  places,  a  uniform  standard  should  be  adopted 
to  which  all  populations  may  be  referred,  or  with  which 
they  may  be  compared.  The  committee  on  nomencla- 
ture of  the  American  Public  Health  Association,  in  its 
report  for  1895,  states  that,  other  things  being  equal,  a 
city  in  which  the  persons  living  under  one  year  of  age, 
and  those  who  are  more  than  fifty  years  of  age,  constitute 
together  more  than  15  per  cent,  of  the  population,  will 
have  a  higher  death-rate  than  another  city  under  similar 
conditions  in  which  the  persons  of  these  ages  constitute 


S^O  VITAL  STATISTICS. 

less  than  lo  per  cent,  of  the  population,  since  the  death- 
rate  at  these  age-periods  is  invariably  much  higher  than 
that  of  the  remaining  population,  constituted  as  it  is  of 
children  who  have  passed  the  first  and  most  critical  year 
of  infancy,  together  with  the  vigorous  population  of  early 
adult  life.  For  example,  in  the  comparatively  new  popu- 
lations of  such  States  or  territories  as  Arizona,  Nevada, 
Idaho,  and  the  older  state  of  Iowa,  the  ratios  of  persons 
of  the  two  age-groups,  under  one  year  and  all  over  fifty, 
were  as  follows,  by  the  census  of  i< 


Per   Cent,   of   Persons  under  One  and  over   Fifty  Years   to   the 
Total  Population. 

Arizona 8.90  per  cent. 

Idaho 12.64       '■ 

Nevada 10.52       " 

Iowa 13-99       " 

On  the  other  hand,  the  per  cent,  of  persons  living  at 
these  age-periods  in  the  two  older  States  of  Delaware  and 
Vermont  was  as  follows: 

Delaware 15-92  per  cent. 

Vermont -21.85        " 

Now,  since  the  death-rate  of  children  under  one  year 
is  usually  from  eight  to  ten  times  as  great  as  that  of  the 
total  population,  and  that  of  persons  over  fifty  is  usually 
not  far  from  twice  as  large,  it  follows  that,  other  things 
being  equal,  we  may  expect  to  find  a  general  death-rate 
in  these  older  States  correspondingly  greater  than  that  of 
the  newer  communities. " 

The  committee  advocated  the  adoption  of  the  method 
recommended  by  Korosi,  of  Budapesth,  as  being  the 
most  simple,  the  least  cumbrous,  and  the  one  that  is  suf- 
ficiently accurate  for  the  purposes  for  which  it  is  designed. 
Korosi's  method  comprises  a  division  into  four  age-groups, 
as  follows:  Under  one  3'ear,  one  to  twenty  3^ears,  twenty 
to  fifty  years,  all  over  fifty  years. 

Korosi  also  recommends  that  the  age-distribution  of 


BIR TH-RA  TE  AND  DEA  TH-RA  TE.  $21 

only  one  country,  for  example,  that  of  Sweden,  be  em- 
ployed as  standard.  The  distribution  of  Sweden  by  the 
census  of  1880  was  as  follows: 

Age-period.  Per  cent. 

Under  one  year 2.65 

One  to  twenty  years 39-8l 

Twenty  to  fifty  years 38.62 

All  over  fifty 18.92 

The  method  of  application  is  as  follows,  as  applied  to 
Massachusetts: 


Age-groups. 

Standard  distribution, 
Sweden,  1880. 

Death-rate,  Massachu- 
setts, 1880. 

Mortality  index. 

O-I 

1-20 

20-50 

all  over  50 

2.65 
39.81 
38.62 
18.92 

19.13  per  cent. 
1.28    "      " 
1.03    "      " 
3.90    "      " 

5-07 
5-09 
3-98 
7.38 

100.00                   1 

21.52 

In  Dr.  Ogle's  standard,  which  is  in  use  in  England, 
the  population  is  divided  into  twelve  age-groups.  These 
groups,  and  the  annual  rate  of  mortality  in  England  per 
1000  persons  living,  are  shown  in  the  following  table  from 
the  Registrar-General's  report  for  i^ 


All 
ages. 

0 
to 
5 

5 
to 
10 

10 
to 

15 

15 
to 
20 

20 
to 

25 

25 

to 
35 

35 
to 
45 

45 
to 
55 

55 
to 
65 

65 
to 

75 

75 
to 
85 

85  and 
upward. 

England,    average"] 
annual     rate    in 
twenty-five   yrs.  ( 
1848-72. 

22.4 

67.9 

8.3 

4.8 

6.7 

8.8 

9-9 

12.7 

17.0 

30.1 

62.0 

139.6 

294.2 

England,  1880   .   .    . 

20.5 

64.4 

6.3 

3-3 

4.8 

6.1 

7-7 

II. 5 

16.0 

30-4 

61.2 

131-3 

257.9 

The  rate  at  each  age-group  is  corrected  to  the  propor- 
tion of  the  population  at  that  age.  The  division  into 
twelve  age-groups,  instead  of  four,  increases  the  labor  of 
computation  threefold. 

Calculation  of  the  Birth-rate  and  Death-rate. — 
The  birth-rate  and  the  death-rate  are  both  calculated  at 


522  VITAL  STATISTICS. 

an  annual  rate  per  looo  of  population.  The  births  may 
be  divided  into  several  groups  according  to  sex,  race,  or 
as  regards  legitimate  and  illegitimate  births.  Death-rates 
are  of  special  value  when  calculated  for  different  occupa- 
tions, different  diseases,  and  different  age-groups.  This 
information  is  of  value  because  it  indicates  the  occupa- 
tions most  injurious  to  health,  and  also  the  ages  at  which 
most  deaths  occur.  Death-rates  from  the  various  ex- 
anthemata are  also  of  special  importance,  because  the 
course  of  an  epidemic  can  be  traced  by  this  means;  its 
relative  severity  can  be  compared  with  preceding  epi- 
demics; and  especially  the  value  of  compulsory  vaccina- 
tion can  be  ascertained  from  the  statistics  of  small-pox. 
The  following  formula  is  readily  remembered,  and  will 

facilitate  the   calculation   of  death-rates:   M= — -  —  ex- 

preSvSed  in  thousands,  where  M  =  the  mortality,  D  =  the 
number  of  deaths,  and  P  =  the  population. 

Exmnple. — In  a  population  of  2000  there  are  30  deaths, 

hence  the  death-rate  is 2_  =  ic  per  1000  of  pop- 

2000  ^  ^  ^  ^ 

ulation.  The  death-rate  from  a  particular  disease  is 
expressed  as  so  many  per  10,000  of  population,  and  the 
fatality  of  a  disease  is  expressed  in  per  cent,  of  the  num- 
ber of  cases.  The  death-rate  of  a  place  is  also  influenced 
by  other  than  the  sanitary  conditions  of  a  place,  such  as 
the  prevailing  diseases  of  the  locality,  the  nature  of  the 
occupations,  the  relative  ages  of  the  population,  etc. 

Rate  of  Infant  Mortality. — The  rate  of  infant  mor- 
tality is  measured  by  the  proportion  of  deaths  of  infants 
under  one  year  of  age,  to  the  number  of  births  registered, 
and  is  expressed  as  so  many  per  1000  births.  Stillbirths 
are  excluded.  The  infant-mortality  is  considered  to 
be  one  of  the  best  tests  of  the  sanitary  condition  of  a 
locality,  though  this  cannot  apply  to  newly  settled  locali- 
ties, where  the  infant  population  is  necessarily  quite 
small. 

Death-rate  of  Persons  Engaged  in  Various  Occu- 


MEAN  DURA  TION  OF  LIFE.  523 

pations. — The  influence  of  occupation  can  be  definitely 
determined  only  by  studies  of  the  death-rate  of  persons 
following  those  occupations,  and  this  is  done  by  deter- 
mining the  ratio  of  deaths  at  each  age  to  those  living 
during  a  certain  time  and  engaged  in  the  same  occupa- 
tion. 

Mortality  in  Relation  to  Seasons. — The  influence 
.of  the  weather  in  favoring  the  production  of  certain  dis- 
eases is  shown  in  the  death-rate  from  those  diseases  at 
certain  seasons  of  the  year;  thus  in  winter  there  are  a 
greater  prevalence  and  a  higher  death-rate  from  diseases 
of  the  respiratory  system,  while  in  summer  there  are  a 
greater  prevalence  and  a  higher  death-rate  from  diseases 
of  the  gastro-intestinal  tract.  As  a  rule,  the  mortality  is 
highest  during  the  winter  months,  though  where  there  is 
a  large  infant  population  the  death-rate  is  frequently 
highest  in  summer  because  of  the  prevalence  of  infantile 
diarrhea. 

Mean  Age  at  Death. — The  mean  age  at  death  of  a 
population  is  the  sum  of  the  ages  divided  by  the  number 
of  deaths.  Due  corrections  must  be  made  for  a^e  and 
sex  distribution  if  these  are  not  in  accord  with  those  of 
the  general  population.  A  large  infant  population  will 
reduce  the  mean  age  at  death  though  the  health  of  the 
adult  population  is  extremely  good.  De  Chaumont  gives 
the  following  formula  for  the  approximate  calculation  of 

the  mean  duration  of  life:    (  -  X     -  |  +  (  -  X  —  |=x, 

\  3         I)  /        \  3        B  ' 
where  B  =  the  birth-rate,   D  =  the  death-rate  pei   unit 
of  population  {i.  e.^  35  per  1000  =  0.035  per  unit). 

Example. — In  England  between  1871  and  1880  B  = 
35.35  per  1000  ■=  0.03535  per  unit  of  population.  D,  for 
the  same  period,  =  21.4  per  1000  =  0.0214  per  unit  of 

population,  then  x  =  (  -    X   )   +  I  -    X ) 

\3         0.0214/         \3         0.03535/ 

=  40.58  years  ^  the  expectation  of  life  at  birth. 

Mean  Duration  of  I/ife. — The  mean  duration  of  life 

is  the  expectation  of  life  at  birth,  and  at  any  other  age  it 


524 


VITAL  STATISTICS. 


is  expectation  of  life  at  that  age,  as  taken  from  life  tables, 
added  to  the  age. 

Probable  Duration  of  I^ife. — The  probable  duration 
of  life  is  the  age  at  which  a  given  number  of  children 
born  at  the  same  time  will  be  reduced  to  half  the  number. 

Bxpectation  of  I/ife. — The  expectation  of  life  is  the 
average  length  of  time  a  person  of  any  age  may  be  ex- 
pected to  live.  This  is  computed  from  life  tables.  The 
following  life  table  gives  the  results  of  computations 
from  the  mortality  returns  in  England  and  America,  and 
the  results  of  the  experiences  of  life  insurance  companies: 


— ' 

'S 

S. 

ji) 

e 

4) 
> 

uT 

1 

3  6 

0 

0 

rt  c» 

«= 

■"    1 

a 

c3 

00 

4.1 

^ 

,0  i^ 

^  00 

ni 

hb' 

D 

0) 

0 

Z 

1 

•d 

2 

.J5 .,  K 

< 

a 

3    OJ 

t 

B 

■A 
>> 

O'ti 

p. 

s 

3 

6  2 

en  'c 

-  0. 

rt 

l^S' 

Q 

K 

H 

i 

1— > 

Age. 

Males. 

Females. 

Males. 

Females. 

Males. 

Females. 

Males. 

Females. 

Males. 

Females. 

o  yr. 

41-35 

44.62 

41.92 

45-25 

41-74 

43-50 

63-51 

59-63 

I    " 

48.05 

50-14 

48 

64 

50- 75 

49-84 

50.24 

68.33 

63-57 

2  yrs. 

50.14 

52.22 

50 

73 

52.81 

52.17 

52-35 

69.58 

64-^4 

3    " 

50.86 

52.99 

51 

45 

53-57 

52.76 

52-89 

69.78 

64.07 

4    " 

51.01 

53.20 

51 

61 

53-77 

52-93 

53-00 

69.72 

63-73 

5    " 

50.87 

53-08 

m 

47 

53-65 

52-78 

52.88 

69.36 

63.20 

10     " 

47.60 

49.76 

48 

16 

50-32 

49-99 

48.05 

49.92 

50.04 

65-99 

59-84 

15    " 

43 

94 

46.15 

46.57 

44 

19 

45-86 

46.08 

61-75 

55-39 

20      " 

39-40 

41.66 

39 

86 

42.10 

43-07 

40 

82 

42-17 

42.78 

57-44 

50-93 

25    ''- 

36 

05 

38.36 

39-49 

37 

80 

39-04 

39-78 

53-24 

46.65 

3°    " 

32.10 

34-41 

32 

47 

34-75 

35-85 

34 

89 

35-68 

36.70 

49.22 

42.62 

35    " 

28 

88 

31.12 

32-17 

31 

78 

32-32 

33-63 

44-74 

38.47 

40    " 

25.30 

27.46 

25 

59 

27.68 

28.48 

28 

48 

■28.86 

30-29 

40.30 

34-31 

45    " 

22 

34 

24.21 

24. 82 

25 

02 

25-41 

26.95 

35-83 

30-43 

50    " 

18.93 

20.68 

'? 

14 

20.80 

21.24 

21 

33 

22.02 

23.50 

31.10 

26.30 

55    " 

16 

09 

17-37 

17.80 

17 

73 

18.63 

20.05 

26.74 

22.30 

60    " 

13-14 

14.24 

13 

31 

14-32 

14.56 

14 

37 

15.60 

16.91 

25-52 

18.45 

6S    " 

10 

79 

"-5S 

11.60 

II 

31 

12.57 

13-77 

18.93 

15.23 

70    " 

8.27 

8.95 

8 

44 

9.08 

8.17 

8 

12 

10.32 

11.30 

15-25 

12.82 

75    " 

6 

52 

7.04 

6.72 

6 

34 

8.08 

8.83 

12.61 

11.07 

80    " 

4-79 

5-20 

4 

96 

5-38 

4-87 

4 

49 

6.86 

7-37 

10.35 

9.07 

85    •' 

3 

78 

4-15 

3-40 

3 

08 

5-63 

5.91 

7-50 

7.50 

90    " 

2.84 

2. go 

2 

88 

3-16 

2.17 

2 

05 

95    " 

2.17 

2.17 

2 

20 

2.40 

1-34 

1 

34 

100 

1.68" 

1.76 

I 

72 

1.84 

In  order  to  construct  such  a  table,  we  must  know  the 
number  of  persons  living,  their  ages,  the  number  of 
deaths,  and  the  ages  at  death,  and  changes  in  population 
caused  by  unusual  birth-rate,  by  emigration,  immigration, 
and  other  causes. 


DENSITY  OF  POPULA  TION  AND  DEA  TH-RA  TE.  525 

The  expectation  of  life  of  females  is  greater  than  that 
of  males  according  to  the  results  obtained  in  England 
and  in  ^Massachusetts.  The  reverse  is  the  case  with  the 
Jews  of  the  United  States.  In  the  experience  of  the 
thirty  life  insurance  companies  of  America  the  expecta- 
tion of  life  of  males  is  greater  than  that  of  females.  This 
most  interesting  result  obtained  from  the  selected  lives 
of  the  insured  is  difficult  to  explain.  The  relatively 
greater  number  of  males  insured  may  explain  this  differ- 
ence in  the  result. 

The  results  obtained  in  England  and  Massachusetts 
indicate  that  the  female  mortality  is  lower  than  the  male 
mortality,  and  it  is  evident,  therefore,  that  the  dangers 
connected  with  childbearing  do  not  prevent  the  general 
female  mortalitv  at  childbearinsa:  ag-es  from  beinsf  lower 
than  that  of  males. 

The  causes  of  the  higher  mortalitv  among  males  are 
largely  connected  with  the  greater  hardships  and  dan- 
gers connected  with  their  occupations.  In  spite  of  the 
dangers  of  childbirth,  married  women  have  a  much  lower 
mortality  than  spinsters  or  widows.  Widows  of  twenty 
to  twenty-five  years  of  age  have  a  higher  mortality  than 
bachelors  and  married  men  of  the  same  age. 

The  expectation  of  life  after  the  first  year  increases  up 
to  the  fourth  year,  and  remains  higher  than  at  the  first 
year  up  to  about  the  seventeenth  year.  Willich  gives 
the  following  formula  for  the  approximate  calculation 
of  the  expectation  of  life  at  any  age:  Expectation  of 
■  life  = -|(8o  —  rt)  =  jr,  where  «  =  the  present  age,  and  .r  = 
the  expectation  of  life.  Thus  at  forty  years,  f  X  (80  — 
40)  =  26.66  years. 

Relation  of  Density  of  Population  to  the  Death- 
rate. — The  relation  of  the  density  of  the  population  to 
the  death-rate  is  most  important.  Dr.  Farr  found  that 
the  mortality  increases  with  the  density  of  the  popula- 
tion, but  not  in  direct  proportion  to  the  density,  but  as 
its  sixth  root.  Thus  if  D  and  D'  =  density  of  the  popu- 
lation in  two  places,  and  JVI  and  J/'  the  mortality,  then 


526  VITAL  STATISTICS. 

M' «r^' 

T>  —  •*/ —      The  death-rate  in  each  locality  is,  however, 

influenced  by  other  factors  than  the  mere  fact  of  the 
existence  of  a  certain  number  of  persons  in  a  specified 
area.  The  most  important  factors  which  influence  the 
death-rate  under  all  conditions  are  the  proportion  which 
the  infant  population  bears  to  the  whole,  or,  in  other 
words,  the  average  age  of  the  population,  the  nature  of 
the  occupation  of  the  people,  and,  above  all,  the  general 
sanitary  conditions  of  the  surroundings. 

Necessity  of  System  of  Notification. — Vital  statis- 
tics cannot  be  obtained  without  some  system  of  notifica- 
tion. Various  objections  have  been  raised  against  the 
notification  of  infectious  diseases.  The  objection  is 
frequently  made  that  the  friends  of  the  patient  wish  to 
keep  the  matter  secret,  and  that  notification  is  a  betrayal 
of  confidence.  There  is  usually  delay  in  calling  a  phy- 
sician, and  this  gives  opportunity  for  the  spread  of  the 
disease.  The  physician  must  be  held  responsible  for 
reporting  infectious  diseases,  otherwise  the  certainty  of 
prompt  notification  is  limited.  The  physician  should  be 
compensated  for  this  extra  work,  though  this  is  rarely 
done,  and  physicians  should  feel  it  a  privilege  to  make 
the  notifications,  because  it  is  the  right  of  only  those 
who  are  authorized  to  practise  in  a  locality.  It  is, 
therefore,  one  mode  of  protecting  the  registered  phy- 
sicians against  the  invasion  of  those  who  are  not  quali- 
fied. 

The  notification  of  infectious  diseases  frequently  causes 
great  discomfort  and  pecuniary  loss  to  those  who  are 
isolated  in  the  infected  area.  It  interferes  with  the  liberty 
and  comfort  of  a  large  number  of  people,  though  this 
discomfort  is  insignificant  to  the  general  discomfort  and 
loss  entailed  by  general  epidemics. 

Dr.  Biddle,  in  a  paper  read  before  the  Seventh  Inter- 
national Congress  of  Hygiene,  on  "Should  Compulsory 
Notification  be  made  General?"  gives  the  mean  death- 
rates  per  looo  living  in  twenty  towns  of  England: 


HOSPITAL  FOR  INFECTIOUS  DISEASES. 


52; 


1871-75. 

1876-80. 

1881-85. 

1886-90. 

All  causes       

24.81 

4-79 
2.17 

23.26 

3-84 
1.47 

21.84 
3-27 
113 

21.19 
2.91 
0.78 

Total  zymotic 

Notifiable  zymotic 

Notification  has  been  in  force  since  the  adoption  of  the 
Public  Health  Act  of  1875.  While  there  was  a  decline 
in  the  death-rate  from  all  causes  from  1871-75  to  1886-90 
of  only  14.5  per  cent,  there  was  a  decline  of  39.2  per 
cent,  in  the  death-rate  from  the  total  zymotic  diseases, 
and  a  decline  of  64  per  cent,  in  the  death-rate  from  the 
notifiable  diseases  during  the  same  period,  showing  the 
great  value  of  notification  in  infectious  diseases. 

Hospital  for  Infectious  Diseases. — Where  satisfac- 
tory isolation  is  impracticable  the  city  should  provide 
special  hospitals  for  infectious  diseases.  This  arrange- 
ment lessens  the  hardships  of  isolation,  and  may  be 
instrumental,  under  proper  regulations,  in  favoring  the 
system  of  notification. 

The  special  need  of  pay  hospitals  for  infectious  diseases 
has  long  been  felt.  Even  where  the  patient  could  be 
satisfactorily  isolated  and  treated  in  the  home,  there  is  a 
feeling  that  the  pecuniary  loss  and  inconvenience  of 
house  quarantine  are  much  greater  than  the  expense  ot 
hospital  treatment.  Consequently  those  that  are  able 
and  willing  to  pay  for  hospital  treatment  cannot  be 
accommodated  anywhere  except  at  the  mimicipal  hos- 
pital, and  there  is  frequently  objection  to  going  to  a 
public  institution.  It  is  safe  to  state  that  the  time  is  not 
far  distant  when  every  large  city  will  have  pay  hospitals 
for  the  reception  of  cases  of  infectious  diseases.  Such 
hospital  treatment  would  overcome  the  obnoxious  house 
quarantine  practised  to-day,  at  least  as  far  as  those  are 
concerned  whose  time  is  most  valuable  from  their  busi- 
ness associations. 


APPENDIX. 


Rules  for  interchange  of  different  expressions  of  results 
of  analysis  : 

To  convert  parts  per  100,000  into  grains  per  gallon 
(=  parts  per  70,000),  multiply  by  0.7. 

To  convert  grains  per  gallon  into  parts  per  100,000, 
multiply  by  1.425. 

To  convert  parts  per  million,  or  milligrams  per  liter, 
into  grains  per  gallon,  multiply  by  0.07. 

To  convert  grains  per  gallon  into  parts  per  million,  or 
milligrams  per  liter,  multiply  by  o.  142. 

To  convert  nitrogen  as  nitrates  into  nitric  anhydrid, 
multiply  by  3.857. 

To  convert  nitric  anhydrid  into  nitrogen  as  nitrates, 
multiply  by  0.2592. 

To  convert  nitrogen  as  nitrites  into  nitrous  anhydrid, 
multiply  by  2.714. 

To  convert  nitrous  anhydrid  into  nitrogen  as  nitrites, 
multiply  by  0.368. 

To  convert  free  or  albuminoid  ammonia  into  parts  of 
nitrogen  as  ammonia,  multiply  by  0.824. 

To  convert  nitrogen  as  ammonia  into  free  or  albu- 
minoid ammonia,  multiply  by  1.214. 

Rules  for  the  conversion  oj  degrees  of  one  thermo7netef 
scale  into  those  of  another  : 

Centigrade  into  Fahrenheit,  multiply  by  9,  divide  by 
5,  and  add  32. 

Fahrenheit  into  centigrade,  deduct  32,  multiply  by  5, 
and  divide  by  9. 

528 


APPENDIX. 


529 


Fahrenheit  into  Reaumur,  deduct  32,  multiply  by  4, 
and  divide  by  9. 

Reaumur  into  Fahrenheit,  multiply  by  9,  divide  by  4, 
and  add  32. 

Centigrade  into  Reaumur,  divide  by  5  and  multiply 
by  4. 

Reaumur  into  centigrade,  divide  by  4  and  multiply 
by  5- 

Rjiles  for  cojiversion  of  kilogram-vieters  i]ito  foot-pounds 
and  foot-toiis.^  and  vice  versa  : 

To  convert  kilogram-meters  into  foot-pounds,  multiply 
by  7.233. 

To  convert  foot-pounds  into  kilogram-meters,  multiply 
by  0.1382. 

To  convert  kilogram-meters  into  foot-tons,  multiply  by 
0.003229. 

To  convert  foot-tons  into  kilogram-meters,  multiply  by 
309- 7- 

Values  of  terms  employed  in  connection  with  fnel-vahie 
of  food  : 

I  calorie  =r  the  amount  of  heat  required  to  warm  I  gram  of  water 
I  degree  centigrade  =  small  calorie. 

I  kilogram-calorie  =  the  amount  of  heat  required  to  warm  I  kilo- 
gram of  water  i  degree  centigrade  =  large  calorie. 

The  mechanical  equivalent  of  I  calorie  =  3100  foot-pounds. 

Comparison  of  Metric  and  English   Weights  and  Meas- 
ures •' 

~ LENGTH. 
I  meter  =  39.37    inches  =  3.28  feet. 

I  decimeter   =    3.94         "      =4  inches,  nearly. 
I  centimeter  :=:    0.394    inch    =  -fj^  inch. 
I  millimeter  =    0.0394     "       =  J.-     "     nearly. 
I  kilometer   ^    1000  meters  =  1094  yards  =  f  mile,  nearly. 
I  mile  =    1609        "      or  1.609  kilometers. 

I  yard  =    0.9144  meter. 

I  foot  =    0.3048     "        :=  3.048  decimeters. 

I  inch  =  25.4  millimeters. 

34 


53°  APPENDIX. 

CAPACITY. 

I  liter  =  looo  cubic  centimeters  =  6i  cubic  inches  =  35.3 

ounces  =  2.182  pints  ^  0.264  gallon. 
I  cubic  centimeter  =:  0.061  cubic  inch. 
1,000,000  cubic  centimeters  =  looo  liters  =  i  cubic  meter 

=  35.3  cubic  feet. 
I  cubic  meter  ^  265.78  gallons. 
I  cubic  inch  =  16. 4  cubic  centimeters. 
<  I  fluidounce  ;=  28.3  cubic  centimeters  =  1.806  cubic  inches. 
I  cubic  foot  =  7.48  gallons  =   1000  fluidounces  =  28.32  liters. 
I  cubic  yard=  0.7645  cubic  meter. 
I  gallon  =  3785.4  cubic  centimeters  =  3-78S4  liters. 
1,000,000  gallons  =  3785.4  cubic  meters. 


I  cubic  centimeter  of  water  at  4°  C.  (39.2°  F.)  weighs  i  gram. 

I  gram  =  15.432    grains  =  0.035  ounce. 

I  decigram    =r     1. 5432     "       =^  1 5^  grains,  nearly. 

I  centigram  ^    0.15432  grain  =  -^^  grain        " 

I  milligram  =    0.015        "       =  -^^     "  " 

I  kilogram    ==  1000  grams  =  15,432  grains  =  2.2046  lb.  avoir, 

=■  35-3  ounces. 
I  grain  =  65  milligrams,  nearly. 

I  ounce         =  28.35  grams, 

I  lb.  avoir.   =453.6      "       =  0.4536  kilogram. 
I  ton  avoir.  (2240  lbs.)  ^  1016  kilograms. 


I  sq.  meter  ^  10.76  sq.  feet  =  1550  sq.  inches. 

I  sq.  centimeter  =  0.155       ^q.  inch  =  -^■-^    sq.  inch,  nearly. 

I  sq.  millimeter  =  0.00155         "       =  'eso'        "  " 

100  sq.  meters  :=  i  are  =  1 19.7  sq.  yards  ■=  3.954  sq.  rods. 

100  ares  (hektar)    =  11,967  sq.  yards  =  2.47  acres. 

I  sq.  kilometer    =  1,000,000  sq.  meters  =  247  acres  =  0.386 
sq.  mile. 

I  sq.  inch  =  6.452  sq.  centimeters  =  645  sq.  millimeters. 

I  sq.  foot  =  0.0929  sq.  meter  =  9.29  sq.  decimeters. 

I  sq.  yard  =  0.8361        " 

I  acre  ^  40.5  are,  nearly  =  0.405  hektar. 


INDEX. 


.\blution,  amount  of  water  required 

for,  115 
Absolute  humidity,  41 
Acclimation,  51 
Acid,  carbolic,  438 

hydrocj-anic,  437 
Actinomycosis,  425 
Action  of  wind,  72 
Activated  sludge,  166 
Adulterations  of  food,  228 
Adults,  subsistence  diet  for,  233 
Age,  19 

at  death,  average,  by  occupation, 
266 
mean,  525 

diet  for  old,  234 
Age-distribution,  standard  of,  519 
Agents,  physical,  for  disinfection,  440 
Air,  32 

amount  required,  67 
respired,  67 

bacteria  in  expired,  56 

carbon  dioxid  in,  59 

chemical  anatysis  of,  59 

diseases  produced  by  impure,  62 

dust  in,  58 

effects  of  solid  impurities  in,  66 

examination  of,  by  senses,  58 

ground,  52,  335 

hot,  heating  with,  94 

humidifying,  88 

humidity  of,  estimation,  60 

impure,  diseases  produced  by,  62 

impurities  in,  53 
sources  of,  53 

of  dwellings,  impurities  in,  58 

of  factories,  impurities  in,  57 

of  workshops,  impurities  in,  57 

organic  matter  in,  estimation  of,  61 

propeller,  83 

sewer:,  52 

temperature  of,  34 

\-itiated,  effects  of,  63 
-Alcoholic  beverages,  339 
use  of,  in  tropics,  49 
Alimentary  principles  of  food,  194 
Amoeba  coli,  412 


Amount  of  air  required,  67 
respired,  67 
of  exercise  that  should  be  taken,  244 
of  food,  excessive,  282 
of  nutrients  furnished  for  twenty- 
five  cents,  189 
of  water  required  daily,  115 
Analysis  of  air,  chemical,  59 
of  water  and  sewage,  145 
bacteriological,  148 
chemical,  147 
collection  of  samples,  145 
microscopic  examination,  146 
physical  examination,  146 
Anemometer,  portable,  81 
AnUin  dyes,  effects  of,  272 
Animal  foods,  196 
parasites,  411 

prevention  of  infection  with,  423 
Animals,    domestic,    composition    of- 

flesh  of,  207 
Anopheles,  392 

Antimeningococcus  serum,  371 
x\ntistreptococcic  serum,  369 
Antitoxic  sera,  366 
Antitoxin,  diphtheria,  366 

tetanus,  366 
Antituberculosis  serum  of  Marmorek, 

Antityphoid  vaccination  in  army,  320, 

377 
Appendix,  528 
Approximate  composition  of   water, 

114 
Aqueous  vapor,  54 
Arrangement  in  natural  ventilation, 

7.3 
of  interior  of  house,  342 
Artesian  wells,  120 
Artificial  ventilation,  81 

arrangements  for,  84 

comparison  of  methods,  88 

extraction  method,  88 

propulsion  method,  88 
Asiatic  cholera,  in 

detention  of  passengers  on  ac- 
count of,  491 

S3I 


532 


INDEX. 


Asiatic  cholera,  disinfection  for,  491, 

509 
Atmosphere,  humidity  of,  38 

movements  of,  42 

nature  and  composition  of,  3  2 

pressure  of,  35 
distribution  of,  37 
Attitude,  mental,  257 

Bacillus,  tubercle,  action  of  sunlight 

on,  4.30 
Bacteria,  no 

action  of  sunlight  on,  430 

in  clothing,  253 

in  expired  air,  56 

pathogenic,  in  dead  bodies,  390 
persistence  in  dead  bodies,  390 
in  soil,  336 
Bacterial  examination  of  water,  148 
Bacteriolytic  sera,  367 
Baking  powders,  223 
Barometer,  35 
Barracks,  315 
Basis  for  calculation  of  vital  statistics, 

519 
Bedding,  disinfection  of,  504 

infected,  253 
Beef,  lean,  206 
Beriberi,  236 
Berkefeld  filter,  137 
Besredka  method  of  protection,  375 
Beverages,  alcoholic,  227 
use  of,  in  tropics,  49 

non-alcoholic,  227 
Bills  of  health,  473 
Biologic  aids  to  diagnosis,  384 
Birth-rate,  calculation  of,  521 
Blackboards,  position  of,  286 
Board  of  health,  regulations  of,  513 
Bodies,  dead,  pathogenic  bacteria  in, 
390 

of  water,  self -purification  of,  122 
Body,  chemical  composition  of,  178 
Boil,  Oriental,  415 
Boiler-purposes,  suitability  of  water. 

Boiling- water,  138 

Boophilus  bovis  and  Texas  fever,  403, 

408 
Bowels,  regular  attention  to,  255 
Bread,  222 
Buildings,  defects  in,  292 

loss  of  heat  from,  90 
Butter,  219 

adulteration  of,  229 

Cabins,  disinfection  of,  503 
Cameron  septic  tank,  166 


Camp,  diseases  in,  318 
location  of,  312 
sanitary  policing  of,  313 
Camps,  312 
Cancer,  114 
Canned  vegetables,  adulteration  of, 

230 . 
Capacity  of  soil,  drainage,  281 
Carbolic  acid,  438 
Carbon  dioxid,  53,  62 

in  air,  estimation  of,  59 
monoxid,  62 
Card,  inspection,  480 
Cargo,  disinfection  of,  498 

inspection  of,  487 
Carriers,  56 
Cattle,    protective    vaccination    of, 

against  tuberculosis,  379 
Causes  of  disease,  1 7 
exciting,  19 
immediate,  17 
predisposing,  19   • 
remote,  18 
vital,  352 
Census,  basis  for  calculation,  519 
Cereals,  composition  of,  221 
Certified  milk,  218 
Cheese,  220 

Chemical  analysis  of  air,  59 
of  sewage,  147 
of  water,  147 
composition  of  air,  32 
of  body, 178 
of  water,  100 
treatment  of  sewage,  160 
Childhood,  diet  in,  233 
Chlorinated  lime,  439 
Cholera,  Asiatic,  in 
disinfection  for,  491,  509 
protective  inoculation  against,  376 
quarantine  regulations  on  account 
of,  479,  491 
Cholera-infected  vessels,  treatment  of, 

491 
Circulation,  effect  of  exercise  on,  241 
City,  killing  of  mosquitoes  in,  398 
Cleaning  house,  350 
Cleanliness  in  relation  to  clothing,  252 

of  mouth  and  teeth,  255 
Cleansing  the  vessel,  327 
Climate,  44 

influence  upon  health,  46 
upon  mortality,  50 
Cloak-rooms,  286 
Closet,  water-,  151,  290 

amount  of  water  required  for,  115 
Clothing,  247 

cleanliness  in  relation  to,  252 

infected,  253 


INDEX. 


533 


Clothing,  injurious  efifects  of,  251 

of  the  soldier,  30S 
Clouds,  43 

Cocoa,  adulteration  of,  230 
Coffee,  adulteration  of,  230 
Cold,  protection  against,  247 
Collection  and  removal  of  garbage, 

174 
of  samples  of  water,  145 
Combination  systems  of  heating,  97 
Combustion,  effects  of  air  vitiated  by, 

.    65   .  . 

impurities  due  to,  57 
Commercial  value  of  sewage,  171 
Comparative  mortalit}^,  263,  265 
Comparison  of  methods  of  ventilation, 

88 
Complement,  364 
Composition  of  cereals,  221 

of  different  kinds  of  meat,  208 

of  drinking-water,  100,  114 

of  flesh  of  domestic  animals,  207 

of  food  materials,  190,  193 

of  leguminosae,  222 

of  meat,  206 

of  the  atmosphere,  32 
Condiments,  227,  228 
Conditions  of  environment,  hygienic, 

26 
Configuration  of  soil,  338 
Conjugal  conditions,  26 
Connate  conditions,  24 
Consumption  of  fluids,  228 
Control  of  sale  of  milk,  municipal,  215 
Conveyances,  public  disinfection  of, 

446 
Cooking,  amount  of  water  required 

for,  IIS 
Cooling  devices,  346 
Correct  soles,  249 
Corridors,  286 
Corrosive  sublimate,  437 
Cost  of  food,  189 
Covering  of  floors,  344 

of  walls,  344 
Cows,  care  of,  217 

milk,  208 
Creolin,  448 
Crew,  inspection  of,  481 
Cubic  space,  69,  282 

relation  to  window  space,  284 
Culex,  393 


Daily  amount  of  water  required,  115 

diet,  minimum  standard  of,  186 
Dairy  rules,  216 
Damp  soil,  improvement  of,  338 
Dampness,  protection  against,  248 


Dark  meat,  effect  of,  205 

Dead  bodies,  pathogenic  bacteria  in, 

390 
Death  from  certain  causes  in  persons 
over  sixty  years  of  age,  21 

mean  age  at,  523 

percentage  and  total  mortality  at 
different  periods  of  life,  20 

relative  number  among  males  and 
females,  22 

reported  and  rates  of  tuberculosis 
and  syphilis,  25 
Death-rate,  calculation  of,  521 

in  different  occupations,  522 

relation  to  population,  525 
Deehan's  test  in  typhoid  fever,  385 
Defects  in  school-buildings,  292 
Deformed  feet,  250 
Degree  of  warmth,  90 
Dengue  and  animal  parasites,  418 
Density    of   population,    relation    to 

death-rate,  525 
Dermacentor  occidentalis,  408 
Desks,  291 

Destruction  of  mosquitoes  in  the  city, 
398 

of  vermin,  400 
Detection  of  meat  preservatives,  203 
Detention  period,  456 
Diagnosis,  biologic  aids  to,  384 
Diarrhea,  113 

hUl,  109 

infantile,  113 
Diet  for  old  age,  234 

in  childhood,  233 

in  infancy,  232 

subsistence,  for  adults,  233 
Dietaries,  232 
Dietary,  standard,  186 
Dieting,  178 

Difference  in  temperature,  72 
Different  varieties  of  food,  196 
Diffusion,  72 

of  gases,  67 
Digestibility  of  food,  191 
Dilution,  123 

Diphtheria,      active      immunization 
against,  378 

antitoxin,  366 

isolation  and  disinfection  in,  453 
Direct  heating,  91 

radiation,  93,  94 
Direct-indirect  radiation,  94 
Disease,  17 

among  marines,  ZZZ 

conveyed  through  milk,  210 

exciting  causes  of,  19 

from  which  soldiers  suffer  in  peace 
time,  318 


534 


INDEX. 


Disease,  immediate  causes  of,  1 7 

in  camp,  318 

industrial,  special,  274 

infectious,  disinfection  in,  444 
hospitals  for,  527 
preventive  measures  for,  388 

insects  and,  402 

interstate  notiiication  of,  507 

intestinal,  disinfection  in,  443 

predisposing  causes  of,  19 

produced  by  diseased  meat,  197 
by  impure  air,  62 

quarantinable,  473,  507 

remote  causes  of,  18 

respiratory,  disinfection  in,  443 

vital  causes  of,  352 

which   cause   most   deaths   among 
soldiers  in  peace  time,  318 
Disinfectants  authorized  by  quaran- 
tine laws,  499 

in  common  use,  430 
Disinfecting  plant,  steam,  431 
Disinfection,  428 

and  isolation,  value  of,  452 

for  cholera,  491,  509 

for  leprosy,  496 

for  plague,  494 

for  small-pox,  495,  510 

for  typhus  fever,  496,  510 

for  yellow  fever,  492,  509 

in  quarantine,  511 

of  barber-shops,  448 

of  excreta,  441 

of  habitations,  444 

of  infective  materials,  441 

of  libraries,  448 

of  patient,  445 

of  public  conveyances,  446 

of  sick-room,  442 
in  exanthemata,  442 
in  intestinal  diseases,  443 
in  other  infectious  diseases,  444 
in  respiratory  diseases,  443 

of  vessels,  498,  503 
cabins,  498,  503 
cargo,  503 
forecastle,  503 
holds,  503 
steerage,  504 
■  of   water    with   ultra-violet   light, 

143 

on  large  scale,  431 
Disposal  of  garbage,  173,  175 

of  sewage,  151,  158,  289 
Dissemination,  modes  of,  354 
Dissolved  impurities  in  water,  109 
Distillation  of  water,  138 
Distribution  of  atmospheric  pressure, 

37 


Domestic    animals,    composition    of 
flesh  of,  207 

filter,  137 

ports,   quarantine   regulations   for, 
486 

water-still,  138 
Drainage,  348 

capacity  of  the  soil,  281 
Driniing- water,  amount  required,  1 14 

composition  of,  114 

odors  in,  107 
Dry  heat,  440 
Dry-earth  closet,  157 
Duration  of  life,  mean,  523 

probable,  524 
Dust  in  air,  58 

removal  of,  86 
Dwellings,  air  of,  58 
Dysentery,  113 

prophylactic  immunization  against, 
378 


Effect  of  exercise  on  the  circulation, 
241 
on  the  elimination  of  nitrogen, 

243 
on  the  lungs,  239 
on  the  muscles,  242 
on  the  nervous  system,  243 
on  the  nitrogen  elimination,  243 
Effects,  injurious,  of  clothing,  251 
of  impurities  in  water,  108 
of  light  and  dark  meat,  205 
of  solid  impurities  in  air,  66 
of  vitiated  air,  63,  64 
of  wind  upon  health,  43 
Eggs  as  food,  220 
Ehrlich's  hypothesis,  360 
Elastic  force  of  vapor,  41 
Electricity,  heating  with,  98 
Elimination  of  nitrogen,  effect  of  exer- 
cise on,  243 
Emscher  tank,  167 
Energy  derivable  from  food,  182 

potential,  in  food,  180 
Entrance,  avenues  of,  388 
Environment,  hygienic  condition  of, 

26 
Epidemics,  nature  of,  355 
Establishments,    industrial,    lighting 

of,  278 
Etiologic  factor  in  infectious  diseases, 

388. 
Examination  of  air  by  senses,  58 
of  water,  bacterial,  148 
chemical,  147 
microscopic,  146 
physical,  146 


INDEX. 


535 


Exanthemata,  disinfection  in,  442 

Excessive  amounts  of  food,  influence 
of,  235 

Exciting  causes  of  disease,  19 

Excreta,  disinfection  of,  441 

Exercise,  239 

amount  that  should  be  taken,  244 
effect  on  the  circulation,  241 

on  the  elimination  of  nitrogen, 

243 
on  the  lungs,  239 
on  the  muscles,  242 
on  the  nervous  system,  243 
on  the  nitrogen  elimination,  243 

Exhaust  steam-heating,  96 

Expectation  of  life,  524 

Expired  air,  bacteria  in,  56 

Extermination  of  rats,  401 

Extraction  and  propulsion  method  of 
ventilation,  88 


Factories,  impurities  in  air  of,  57 

Fans,  82 

Fatigue,  242 

Feet,  deformed,  250 

normal,  250 
Fever,  scarlet,  isolation  and  disinfec- 
tion in,  454 

typhoid,  III 

tj^hus,  disinfection  in,  510 

yellow,  509 
Filaria  and  mosquitoes,  405,  419 
Filter,  Berkefeld,  137 

construction,  137 

domestic,  137 

mechanical,  133 

sand, 124 
Filtering  medium,  137 
Filters,  household,  136 

sand,  124 

spriiikling,  168 
Filtration,  123 

intermittent,  125 

mechanical,  132 

purification  without,  137 

sand, 124 

through  coarse  broken  stone,  165 
Fire  as  a  disinfectant,  440 
Fireplaces,  open,  94 
Fish,  208 
Flask  method  of  estimating  carbon 

dioxid  in  air,  60 
Fleas  and  disease,  405 

remedies  for,  408 
Flesh   of   domestic   animals,   compo- 
sition, 207 
Flies  and  disease,  404 

killing  of,  397 


Flies,  protection  from,  351 
Floor  space,  282,  284 
Floors  and  floor  covering,  344         • 
Fluids,  consumption  of,  228 
Food,  adulterations  of,  2 28 

alimentary  principles  of,  194 

and  dieting,  178 

animal,  196 

composition  of,  193 

digestibility  of,  191 

eggs,  220 

energy  derivable  from,  182 

influence  of  excessive  amounts,  236 
of  insuflicient  amounts,  235 

materials,  composition  of,  190 

mineral,  226 

nutritive  value  and  cost,  189 

nuts  as,  226 

potential  energy  of,  180 

preservatives,  225 

water  as,  195 
Food-poisoning,  200 
Food-supply,  328 
Foods,  adulteration  of,  228 

animal,  196 

vegetable,  221 
preserved,  336 
Foot  inspection,  322 
Forbes'  water  sterilizer,  139 

army  type,  314 
Force  of  vapor,  elastic,  41 
Forecastle,  disinfection  of,  503 
Foreign  ports,  quarantine  regulations 

at,  473 
Formaldehyd,  432 

disinfection  with,  500 

generation  of,  433 
Formaldehyd-spraying  liquid,  436 
Foundation  of  house,  341 
Fresh  air,  amount  required,  67 

respired,  67 
Friction,  81 
Frontiers,  quarantine  regulations  at, 

497 


Game,  208 
Garbage,  173 

collection  and  removal,  174 

disposal,  173,  175 
Garments,  outer,  309 
Gas,  formaldehyd,  disinfection  with, 
500 
generation  of,  500 

heating  by  means  of,  99 
Gaseous  impurities  in  water,  108 
Gases,  diffusion  of,  67 
General  regulations,  quarantine,  507 

requirements  at  quarantine,  489 


536 


INDEX. 


General  rules  for  ventilation,  71 
Generation  of  formaldehyd  gas,  433 
Glanders,  reaction  in,  385 
Goiter,  114 
Ground-air,  52,  335 
Ground-water,  102,  336 
supplies,  119 


Habitations,  256,  340 

disinfection  of,  444 
Haffkine  fluids,  375 

method  of  protection,  374 
Hard  water,  softening  of,  141 
Health,  17 

bills  of,  473 

effects  of  wind  upon,  43 

influence  of  climate  upon,  46 
of  humidity  upon,  42 

of  laborers,  276 

State  board  regulations  of,  513 
Heat,  81 

drj',  440 

emitted  by  radiation,  92 

loss  of,  from  buildings,  90 

moist,  440 

protection  against,  248 

supplied  by  radiating  surfaces,  91 
Heating,  90,  288,  345  _ 

by  means  of  electricity,  98 
of  exhaust  steam,  96 
of  gas,  99 
of  hot  air,  98 

water,  96 
of  open  fireplaces,  93 
of  petroleum,  99 
of  steam,  95 
of  stoves,  94 

combination  systems  of,  97 

direct,  91 

indirect,  91,  97 

of  the  vessel,  327 

systems  of,  93 
Helminthiasis,  419 
Heredity,  22 
Hill  diarrheas,  109 
Holds,  disinfection  of,  503 
Hookworm  disease,  423 
Hospitals  for  infectious  diseases,  527 
Hot  air,  heating  with,  98 
Hot-water  radiators,  95 
House,  foundation  of,  341 

position  of,  340 

quarantine,  452,  513 

roof  of,  341 

walls  of,  341 
House-cleaning,  341 
Household  filters,  136 
Houses  for  the  poor,  348 


Houston's  sewage  streptococcus,  106 
Humidifying  air,  88 
Humidity  of  the  atmosphere,  38 
absolute,  41 
estimation  of,  60 
influence  on  health,  42 
relative,  41 
Hydrocyanic  acid,  437 
Hydrogen  sulphid,  62 
Hygiene,  28 

definition  of,  17 

development  of,  29 

industrial,  258 

military,  302 

naval,  324 

personal,  254 

school,  281 
Hygienic  conditions  of  environment, 

26 
Hygrometer,  39,  61 
Hygrometry,  39 


Immediate  causes  of  disease,  17 
Immune  body,  364 

sera,  typhoid,  367 
Immunity,  356 
active,  358 

prevention  of  infection  by  induc- 
ing, 373 
against  malaria,  395 
Ehrlich's  hypothesis  of,  360 
passive,  358 
Immunization,  active,  against  diph- 
theria, 378 
prophylactic,  against  dysentery,  378 

paratyphoid  fever,  378 
protective,  against  whooping-cough, 
378 
Improvement  of  a  damp  soil,  338 
Impure  air,  diseases  produced  by,  62 
Impurities  in  air,  53 
of  dwellings,  58 
of  factories,  57 
of  workshops,  57 
solid,  66 
source  of,  53,  57 

due  to  combustion,  57 
to  perspiration,  56 
to  respiration,  53 
in  water,  103 
effects  of,  108 
gaseous,  108 
inorganic,  109 
organic,  no 
Indirect  heating,  93,  97 
Industrial  diseases,  special,  274 
establishments,  hygiene,  258 
lighting  of,  278 


INDEX. 


537 


Infancy,  diet  in,  232 

Infant  mortality,  rate  of,  522 

Infantile  diarrhea,  113 

Infected  clothes  and  bedding,  253 

compartments,  disinfection  of,  503 

vessels,  treatment  of,  503 
Infection  by  means  of  animal  para- 
sites, prevention  of,  423 

physicians  as  carriers  of,  386 

prevention  of,  by  active  immunity, 

373 
sources  of,  388,  389 
Infectious  diseases,  hospitals  for,  527 
serum  therapy  and  serum  pro- 
phylaxis in,  372 
Infective   materials,    disinfection    of, 

441 
Influence  of  climate  on  health,  46 
on  mortality,  50 
of  excessive  amounts  of  food,  235 
of  humidity  on  health,  42 
of  insufficient  food,  235 
of  length  of  working-day,  276 
Injurious  effects  of  clothing,  251 
Injur>%  protection  against,  249 
Inland  quarantine,  451 
Inoculation,  protective,  against  chol- 
era, 376 
plague,  376 
typhoid  fever,  377 
Insects,  relation  to  spread  of  disease, 

402 
Inspection,  body,  323 
foot,  322 
meat,  197 

method  of,  198 
of  quarantines,  498 
local,  498 
State,  498 
of  schools,  medical,  295 
of  vessels,  477,  487 
card,  480 
Insufficient  food,  influence  of,  235 
Interior  arrangement  of  house,  342 
Intermittent  filtration,  125 
Interstate  notification  of  diseases,  507 
quarantine,  506 

general  regulations  of,  507 
Intestinal  diseases,  disinfection  in,  443 
Iron,  sulphate  of,  439 
Irrigation,  subsurface,  165 
Isolation,  452 
period  of,  456 
value  of,  452 

Jets,  83 

Kai-a-azar,  415 
Killing  of  flies,  397 


Killing  of  mosquitoes,  398 
Koch  method  of  preventing  malaria, 
394 

Laborers,  health  of,  276 
Lake- water,  103 

supplies,  118 
Lard,  adulteration  of,  230 
Latrines,  290,  315 
Laundry,  amount  of  water  required 

for,  IIS 
Law,  milk,  of  Philadelphia,  216 
Laws,  quarantine,  458 
Lean  beef,  206 
Leishmanioses,  415 
Length  of  working-day,  influence  of, 

276 
Leprosy,  quarantine  regulations,  496 
Life,  expectation  of,  524 

mean,  duration  of,  523 

probable  duration  of,  524 
Light  meat,  effect  of,  205 

ultra-violet,   disinfection  of  water 
with,  143 
Lighting,  285,  327 

of  industrial  establishments,  278 

of  the  vessel,  327 
Lime,  chlorinated,  439 

milk  of,  439 

preparations  of,  439 
Liquid  air,  cooling  Ijy,  347 

formaldehyd-spraying,  436 
Local  quarantines,  inspection  of,  498 
Location  of  camps,  312 
Loss  of  heat  from  buildings,  90 
Lungs,  effect  of  exercise  on,  239 

Malaria,  immunity  against,  395 

mosquitoes  and,  392,  405 

prevention  of,  392 
Koch  method,  394 
Malt  liquors,  adulteration  of,  230 
Marches,  317 

Mariners,  diseases  among,  333 
Marines,  selection  of,  329 
Maritime  quarantine,  450,  457 
Marmorek's    antituberculosis    serum, 

371 
Materials,  infective,  disinfection  of, 

441 
Matter,  organic,  54 
Mean  age  at  death,  523 

duration  of  life,  523 
Means,  mechanical,  of  ventilation,  82 
Meat,  196 

composition  of,  206 

effects  of  light  and  dark,  205 

inspection  of,  197 


538 


INDEX. 


Meat,  inspection  of,  method  of,  198 
preservation  of,  202,  224 

detection  of  preservatives,  203 
putrefactive  changes  in,  201 
relative  composition  of,  208 
Mechanical  aids  to  ventilation,  82 
filter,  xi2> 
filtration,  132 
Medical  inspection  of  schools,  295 
Mental  attitude,  257 
Method  of  protection,  Haffkine,  374 
Methods  of  piping,  96 

of  sewage  purification,  162 
sand  filters,  163 
septic  tank,  166 
subsurface  irrigation,  165 
of  ventilation,  71 

extraction  and  propulsion,  88 
natural  and  artificial,  88 
of  water  and  sewage  analysis,  145 
bacteriological,  148 
chemical  analysis,  147 
collection  of  samples,  145 
microscopic  examination,  146 
physical  examination,  146 
purification,  121 
sand  filtration,  124 
self-purification,  122 
Microscopic  examination  of  water,  146 
Microsporon  furfur,  425 
Military  hygiene,  302 
Milk,  adulteration  of,  229 
and  milk  products,  208 
certified,  218 
cows,'  208 

diseases  conveyed  by,  210 
law  of  Philadelphia,  216 
municipal  control  of,  215 
of  lime,  439 
pasteurization  of,  218 
wholesome,  production  of,  216 
Milking,  217 
Mineral  food,  226 

Minimum  standard  of  daily  diet,  186 
Modes  of  dissemination  of  disease, 

354,  388 
Moist  heat,  440 
Moisture,  precipitation  of,  43 
Moral  training  of  the  recruit,  306 
Mortality,  comparative,  263,  264,  265 
infant,  rate  of,  522 
influence  of  climate  upon,  50 
in  relation  to  season,  523 
total  and  death  percentage  at  differ- 
ent periods  of  life,  20 
Moser's  serum,  371 
Mosquitoes,  agents  for  destruction  of, 
504 
and  filaria,  407 


Mosquitoes  and  malaria,  392,  406 
and  yellow  fever,  395,  406 
Anopheles  culex,  392,  393 
killing  of,  398 
protection  from,  351    . 
Mouth,  cleanliness  of,  255 
Movements  of  the  atmosphere,  45 
Muscles,  effect  of  exercise  on,  242 
Mustard,  adulteration  of,  231 
Mutton,  207 


Natural  ventilation,  71 
arrangements  in,  73 
comparison  of,  88 
Nature  of  epidemics,  355 
of  the  atmosphere,  32 
Naval  hygiene,  324 

vessels,   regulations  relating   to, 
498 
Necessity  of  system  of  notification, 

526 
Nervous  system,  effect  of  exercise  on, 

243 

Nevo,  347 

New  York  schools,  control  of  disease 
in,  299 

Nitrate  of  silver,  439 

Nitrobenzine  and  compounds,  effects 
of,  272 

Nitrogen  elimination,  effect  of  exer- 
cise on,  243 

Non-alcoholic  beverages,  227 

Normal  feet,  250 
temperature  and  rainfall,  45 

Notification,   interstate,   of  diseases, 

507 
system  of,  526 
Nutrition,  influence  of  climate  on,  48 
Nutritional  diseases,  236 
Nutritive  value  and  cost  of  food,  189 
Nuts  as  food,  226 


Occupation,  nature  of,  256 
Occupations,  death-rate  in,  522 
Odors  in  drinking-water,  107 
Oidiomycosis,  426 
Oidium  albicans,  426 
Old  age,  diet  for,  234 
Open  fireplaces,  94 
OphthaLmo-diagnostic  test  in  typhoid 

fever,  384 
Opsonic  sera,  369 
Opsonins,  359 
Organic  impurities  in  water,  no 

matter,  54 
in  air,  estimation  of,  61 
Oriental  boil,  415 


INDEX. 


539 


Ornithodoris  moubata,  408 
Outer  garments,  309 
Oxidation,  122 


Parasites,  animal,  411 

prev^ention  of  infection  by,  423 
vegetable,  425 
Paratyphoid  fever,  201 

the    prophylactic    immunization 
against,  378 
Particles,  solid,  in  water,  109 
Passions,  regulation  of,  255 
Pasteurization  of  milk,  218 
Pathogenic  bacteria  in  soil,  338 

persistence  of,  390 
Patients,  disinfection  of,  445 
Pellagra,  237 

Pepper,  adulteration  of,  231 
Period  of  detention,  456 

of  isolation,  456 
Persistence  of  bacteria  in  dead  bodies, 

390 
Personal  hygiene,  254 

prophylaxis,  386 
Perspiration,  impurities  due  to,  56,  63 
Pertussis,     protective    immunization 

against,  378 
Petrolemn,  heating  by  means  of,  99 
Philadelphia,  milk  law  of,  216 
Physical  agents  in  disinfection,  440 

examination  of  water,  146 

properties  of  water,  100 

training  of  the  recruit,  305 
Physicians  as  carriers  of  infection,  386 
Piping,  methods  of,  96 

systems  of,  96 
Piroplasma  of  dengue,  418,  419 
Piroplasmoses,  415 

Plague,  prevention  of  spread  of,  in 
United  States,  511 

protective  inoculation  against,  376 

quarantine  regulations,  494 
Plant,  steam-disinfecting,  431 
Plasmodium  of  malaria,  413 
Plumbing,  348 
Poisoning,  food-,  200 
Policing  of  camps,  sanitary,  313 
Pond- water  supplies,  118 
Poor,  houses  for  the,  348 
Population,    density   of,    relation    to 

death-rate,  525 
Pork,  208 

Ports,    domestic,   quarantine   regula- 
tions for,  486 

foreign  quarantine,  regulations  at, 

473 
of  the  United  States,  regulations  for, 
486 


Position  of  blackboards,  286 

of  the  house,  340 
Potential  energy  in  food,  180 
Poultry,  208 
Powders,  baking,  223 
Precipitation,  122 
mean  annual,  45 
of  moisture,  43 
Predisposing  causes  of  disease,  19 
Preparations  of  lime,  439 
Preservation  of  meat,  202,  224 

detection  of,  203 
Preservatives,  food,  225 
Preserved  vegetable  foods,  224 
Pressure  of  the  atmosphere,  35 

distribution  of,  37 
Prevention  of  infection  by  active  im- 
munity, 373 
by  animal  parasites,  423 
of  malaria,  392 
of  yellow  fever,  395 
Preventive    measures    in    infectious 

diseases,  388 
Probable  duration  of  life,  524 
Proper  soles,  250 

Properties,  chemical,  of  water,  100 
Prophylaxis,  personal,  386 
Propulsion  method  of  ventilation,  88 
Protection  against  cold,  247 
dampness,  248 
heat,  248 
injury,  249 
small-pox,  380 
from  flies  and  mosquitoes,  351 
Haiikine  method  of,  374 
Protozoan  parasites,  41 2 
Psychrometer,  39 
Public   conveyances,   disinfection   of, 

446 
Pimips,  83 

Purification  of  sewage,  methods  of,  162 
Cameron  septic  tank,  166 
sand  filters,  163 
subsurface  irrigation,  165 
of  water,  121 
methods  of,  122 
filtration,  123 
without  filtration,  442 
boiling,  138 
chemicals,  141 
distillation,  138 
sterilization,  141 
Purity,  standard  of,  68 
Putrefactive  changes  in  meat,  201 


QuARANTiNABLE  diseases,  473,  507 
Quarantine,  450 
disinfection  in,  503 


540 


INDEX. 


Quarantine,  foreign  and  insular  regu- 
lations, 477 
general  requirements  at,  489 
house,  452,  513 
inland,  451 
interstate,  506 

general  regulations,  507 
laws,  458 
local,  498 
maritime,  450,  457 
regulations  at  domestic  ports,  486 

at  foreign  ports,  473 

at  ports  of  the  United  States,  486 

at  sea,  484 

on  frontiers,  497 
reservation,  trespassing  on,  468 
State,  inspection  of,  498 

regulations,  511 
treatment  of  vessels  in,  473,  489 


Race,  25     . 

Radiating  surfaces,  heat  supplied  by, 

Radiation,  direct,  93,  94 
heat  emitted  by,  92 
indirect,  93,  97 
Radiators,  steam,  95 

and  hot  water,  96 
Rainfall,  normal,  45 
Rain-water,  loi 
supplies,  116 
Ration,  new,  308 
Rats,  agents  for  destruction  of,  504 

extermination  of,  401 
Receptors,  362 
Records  of  inspections,  483 
Recruit,  302 
training  of,  305 
moral,  306 
physical,  305 
Regulations,  quarantine,  473,  507 
at  domestic  ports,  507 
at  foreign  ports,  473 
Relapsing  fever,  transmission  of,  391 
Relation  of  mortality  to  season,  523 
Relative  humidity,  45 
Remote  causes  of  disease,  18 
Removal  and  disposal  of  garbage,  193 
of  sewage,  151 

Liernur  system,  170 
of  dust,  86 
Remsen's  method  of  estimating  or- 
ganic matter  in  air,  61 
Reports  of  inspections,  483 
Requirements  at  sea,  484 

sanitary,    with    regard   to   vessels, 

477 
Respiration,  impurities  due  to,  53,  63 


Respiratory  diseases,  disinfection  in, 

443 
Ridge  ventilation,  316 
River- water,  102 
Roaches  and  disease,  403 
Roast-beef  hash,  308 
Roof,  341 

Room,  disinfection  of,  444 
Rooms,  size  of,  342 
Rules,  general,  for  ventilation,  71 


Sand  filters,  intermittent,  125 
filtration,  123 

Sanitary  policing  of  camps,  313 
science,  28 

Scarlet  fever,  isolation  and  disinfec- 
tion in,  454 

School  buildings,  defects  in,  292 
hygiene,  281 

Schools,  medical  inspection  of,  295 
New  York,   control   of   disease  in, 
299 

Science,  sanitary,  28 

Scurvy,  236 

Sea,  quarantine  requirements  at,  484 

Sea- water,  103 

Season,  influence  of,  upon  mortality, 

5°. 
relation  of  mortality  to,  523 

Seats,  291 
Sedimentation,  122 
Selection  of  marines,  329 
Senses,  examination  of  air  by,  58 
Septic  tank,  166 
Serum,  antimeningococcus,  371 
antistreptococcus,  369 
antitoxic,  366 

antituberculosis,  of  Marmorek,  371 
antityphoid,  in  army,  320,  377 
bacteriolytic,  367 
diagnostic  test  for  syphilis,  385 
Moser's,  371 
opsonic,  369 

prophylaxis  in  acute  infectious  dis- 
eases, 372 
therapy  in  acute  infectious  diseases, 

372 
typhoid  immune,  367 
Sewage,  analysis,  methods  of,  145 
bacteriological,  148 
chemical,  147 
collection  of  samples,  145 
microscopic  examination,  146 
physical  examination,  146 
chemical  treatment  of,  160 
commercial  value  of,  171 
disposal,  151,  158,  289 
dry  method,  157 


INDEX. 


541 


Sewage  purification,  methods  of,  162 
Cameron  septic  tank,  166 
Emscher  tank,  167 
sand  filters,  163 
subsurface  irrigation,  165 

removal,  151 

Liernur  system,  1 70 

streptococcus,  of  Houston,  106 
Sewer-air,  52 
Sex,  22 

Shoemaker's  soles,  249,  250 
Sickness,  sleeping,  413 
Sick-room,  disinfection  of,  442 
Side  chains,  361 
Silver,  nitrate  of,  439 
Site,  281 

Size  of  rooms,  342 
Sleeping  rooms,  343 

sickness,  413 
Sludge,  activated,  166 

digestion,  165 
Small-pox,  animal  parasites  and,  418 

disinfection  in,  510 

protection  against,  379 

quarantine  regulations,  501,  510 
Soda,  washing,  439 
Softening  of  hard  water,  141 
Soil,  335 

covering,  338 

damp,  improvement  of,  338 

drainage,  capacity  of,  281 

pathogenic  bacteria  in,  338 

pipe,  15s 
Soldier,  clothing  of,  308 

new  ration  for, '308 
Sole,  correct,  249,  250 

shoemaker's,  249,  250 
Solid  impurities  in  air,  effects  of,  66 

particles  in  water,  109 
Sources  of  impurities  in  air,  53 

of  infection  in  infectious  diseases, 
388 

of  water-supplies,  116 
ground- water,  119 
lake  and  pond,  118 
river,  118 
surface  water,  116 
Space,  cubic,  69,  282 

floor,  284 

window,  284 
Special  regulations  relating  to  naval 

vessels,  498 
Sporotrichosis,  427 
Spotted  fever  of  Rocky  Mountains, 

416,  417 
Spring-water,  loi 
Sprinkling  filters,  168 
Stable,  217 
Standard  of  age-distribution,  519 


Standard  of  purity,  68 
State  quarantines,  511 
inspection  of,  498 
regulations,  511 
Statistics,  vital,  517 
Steam  disinfecting  plant,  431 
disinfection  by,  440 
heating  by,  95 
radiators,  95,  97 
Steerage,  disinfection  of,  503 
Stegomyia  fasciata,  396 
Sterilization  of  water  by  chemicals, 

i4i_ 
Sterilizer,  water,  139,  140,  314 
Storage  of  water,  121 
Stoves,  94 

Streptococcus  sewage  of  Houston,  106 
Structure  of  walls,  282 
Sublimate,  corrosive,  437 
Subsistence  diet  for  adults,  233 
Subsurface  irrigation,  165 
Sulphate  of  iron,  439 
Sulphur  dioxid,  436,  499 
Sunlight,  action  of,  on  bacteria,  430 

as  a  disinfectant,  441 
Supplies,  water,  from  ground,  119 
from  lake,  118 
from  pond,  118 
from  rain,  loi 
from  river,  118 
from  spring,  loi,  120 
from  surface,  116 
from  well,  102,  120 
Surface,  configuration  of,  338 

water,  116 
Surfaces,  radiating,  91 
Susceptibility,  356 

Syphilis,  death-rates  from,  for  white 
and  colored  population,  25 
serum  diagnostic  test  for,  385 
System,  Liernur,  170 

nervous,  efi'ect  of  exercise  on,  243 
Systems  of  heating,  93,  97 

of  notification,  necessity  for,  526 
of  piping,  95 


Tea,  adulteration  of,  230 
Teeth,  cleanliness  of,  255 
Temperature  of  the  air,  34 

difference  in,  72 

normal,  45 
Tents,  312 

Tetanus  antitoxin,  366 
Texas  cattle  fever,  416 

and  Boophilus  bovis,  403,  408 
Theatres,  cooling  of,  347 
Training  of  the  recruit,  moral,  306 

physical,  305 


543 


INDEX. 


Traps,  154 

anti-D  trap,  155 

bell-trap,  154 

Mason's  trap,  155 

S-trap,  154 
Treatment  of  infected  vessels,  498 
in  cholera,  491 

of  sewage,  chemical,  160 
Trenner-Lea  formaldehyd  generator, 

434 
Trichinosis,  423 
Trichophyton  fungus,  425 
Trikresol,  438 
Tropical  climate,  influence  on  body,  47 

on  nutrition,  48 
Trypanosomiasis,  413 
Tubercle  bacillus,  action  of  sunlight 

on,  430 
Tuberculosis,    death-rates    from,   for 
white  and  colored  population,  25 
diagnosis,  in  children,  384 
protective    vaccination    of    cattle 
against,  379 
Typhoid  fever,  in 

ophthalmo-diagnostic  test  in,  384 
protective  immunization  against, 

377 
vaccination  in  army,  320,  377 
immune  serum,  367 
Tjqjhus  fever,  animal  parasites  and, 
418 
disinfection  in,  510 
quarantine  regulations,  496,  510 
transmission  of,  405 


Ultra-violet  light,  disinfection  of 
water  with,  143 

Uncinariasis,  423 

Underclothing,  309 

United  States  ports,  quarantine  regu- 
lations for,  486 

Utensils,  milk,  217 


Vaccinated  persons,  quarantine  regu- 
lations for,  480 
Vaccination,    antityphoid,    in    army, 
320,  377 
as  protective  against  small-pox,  379 

tuberculosis  in  cattle,  379 
precautions  in,  383 
Value  of  isolation  and  disinfection,  452 

of  sewage,  commercial,  171 
Vapor,  aqueous,  54 

elastic  force  of,  41 
Veal,  207 
Vegetable  foods,  221 

canned,  adulteration  of,  230 


Vegetable  foods,  preserved,  224 

parasites,  425 
Ventilation,  67,  287,  325,  345 
artificial,  81 

arrangements  for,  84 
comparison  of  methods,  88 
extraction  methods,  88 
general  rules  for,  71 
natural,  71 

arrangements  in,  73 
propulsion  methods,  88 
ridge,  316 
Vermin,  destruction  of,  400,  504 
Vessel,  cleaning  of,  327 
heating  of,  327 
lighting  of,  327 
Vessels,  cholera-infected,  treatment  of, 
491 
disinfection  of,  498,  503 
cabin,  498,  503 
cargo,  503 
forecastle,  503 
holds,  503 

living  compartments,  503 
-  state-rooms,  503 
steerage,  504 
inspection  of,  477 
naval,  in  quarantine,  489 

special  regulations  for,  498 
water-supply  of,  327 
yellow-fever,  infected,  treatment  of, 
492 
Vinegar,  adulteration  of,  231 
Vital  causes  of  disease,  352 

statistics,  517 
Vitiated  air,  effects  of,  63 
Vitiation  by  respiration  and  perspira- 
tion, 63 
Von  Pettenkofer  method  of  estimat- 
ing carbon  dioxid  in  air,  60 


Wall-covering,  344 
Walls  of  house,  341 
structure  of,  282 
Wardrobes,  286 
Warmth,  degree  of,  90 
Washing  soda,  439 
Water  analysis,  method  of,  145 

bacteriological,  148 

chemical,  147 

collection  of  samples,  145 

microscopic,  146 

physical,  146 
and  water-supply,    100,    289,   313, 

327 
amount  required,  115 
as  food,  195 
chemical  composition  of,  100 


INDEX. 


543 


Water,    disinfection   of,   with    ultra- 
violet light,  143 
drinking',  odors  in,  107 
gaseous,  108 
ground-,  102,  119,  336 
impurities  in,  103 

effects  of,  108 
inorganic,  109 
organic,  no 
solid,  109 
lake-,  103 

physical  properties  of,  100 
pond-,  118 
purification  of,  121 
methods  of,  122 
filtration,  123 
self-purification,  122 
without  filtration,  137 
hy  boiling,  138 
by  chemicals,  141 
by  distillation,  138 
by  sterilization,  139 
rain-,  loi 
river-,  102 
sea-,  103 
softening  of,  141 
spring-,  loi 
sterilization  of,  141 
sterilizer,  139,  140,  314 
storage  of,  121 
suitability  for  boiler  purposes,  143 


Water  waste  preventer,  153 

well-,  102 
Water-closet,  151,  290 

amount  of  water  required  for,  115 

wash-down,  153 

wash-out,  152 
Water-supplies,  sources  of,  116 
ground-water,  119 
lakes  and  ponds,  118 
rivers,  118 
surface  water,  116 
Wells,  artesian,  120 
Well-water,  102 

Whooping-cough,  protective  immuni- 
zation against,  378 
Wind,  action  of,  72 

effects  upon  health,  43 
Window  space,  284 
Wooden  vessels,  disinfection  of,  503 
Working-day,  influence  of  length  of, 

276 
Work-rooms,  air  of,  57 
Worms,  parasitic,  419,  420 


Yellow  fever,  disinfection  in,  509 

of  vessels  in,  492 
mosquitoes  and,  395,  405 
prevention  of,  395 
quarantine  regulations,  492,  508, 

509 


OCT'>%lSr; 


